( 8 Jun 94) ************************************** * * * Section 5 - Programmer's Reference * * * ************************************** This section describes features of the GAMESS implementation which are true for all machines. See the section 'hardware specifics' for information on each machine type. The contents of this section are: o Installation overview (sequential mode) o Files on the distribution tape o Names of source code modules o Programming conventions o Parallel version of GAMESS philosophy TCGMSG toolkit installation process execution process load balancing timing examples broadcast identifiers o Disk files used by GAMESS o Contents of DICTNRY master file Installation overview GAMESS will run on a number of different machines under FORTRAN 77 compilers. However, even given the F77 standard there are still a number of differences between various machines. For example some machines have 32 bit word lengths, requiring the use of double precision, while others have 64 bit words and are used in single precision. Although there are many types of computers, there is only one (1) version of GAMESS. This portability is made possible mainly by keeping machine dependencies to a minimum (that is, writing in F77, not vendor specific language extensions). The unavoidable few statements which do depend on the hardware are commented out, for example, with "*IBM" in columns 1-4. Before compiling GAMESS on an IBM machine, these four columns must be replaced by 4 blanks. The process of turning on a particular machine's specialized code is dubbed "activation". A semi-portable FORTRAN 77 program to activate the desired machine dependent lines is supplied with the GAMESS package as program ACTVTE. Before compiling ACTVTE on your machine, use your text editor to activate the very few machine dependent lines in ACTVTE before compiling it. Be careful not to change the DATA initialization! The task of building an executable form of GAMESS is this: activate compile link *.SRC ---> *.FOR ---> *.OBJ ---> *.EXE source FORTRAN object executable code code code image where the intermediate files *.FOR and *.OBJ are discarded once the executable has been linked. It may seem odd at first to delete FORTRAN code, but this can always be reconstructed from the master source code using ACTVTE. The advantage of maintaining only one master version is obvious. Whenever any improvements are made, they are automatically in place for all the currently supported machines. There is no need to make the same changes in a plethora of other versions. The control language needed to activate, compile, and link GAMESS on your brand of computer is probably present on the distribution tape. These files should not be used without some examination and thought on your part, but should give you a starting point. There may be some control language procedures for one computer that cannot be duplicated on another. However, some general comments apply: Files named COMP will compile a single module. COMPALL will compile all modules. LKED will link together an executable image. RUNGMS will run a GAMESS job, and RUNALL will run all the example jobs. The first step in installing GAMESS should be to print the manual. If you are reading this, you've got that done! The second step would be to get the source code activator compiled and linked (note that the activator must be activated manually before it is compiled). Third, you should now compile all the source modules (if you have an IBM, you should also assemble the two provided files). Fourth, link the program. Finally, run all the short tests, and very carefully compare the key results shown in the 'sample input' section against your outputs. These "correct" results are from a VAX, so there may be very tiny (last digit) precision differences for other machines. That's it! Before starting the installation, you should read the pages decribing your computer in the 'Hardware Specifics' section of the manual. There may be special instructions for your machine. Files for GAMESS *.DOC The files you are reading now. You should print these on 8.5 by 11 inch white paper, using column one as carriage control. Double sided, 3 hole, 10 pitch laser output is best! *.SRC source code for each module *.ASM IBM mainframe assembler source *.C C code used by some UNIX systems. EXAM*.INP 21 short test jobs (see TESTS.DOC). BENCH*.INP 13 longer test jobs. These are files related to some utility programs: ACTVTE.CODE Source code activator. Note that you must use a text editor to MANUALLY activate this program before using it. MBLDR.* model builder (internal to Cartesian) CARTIC.* Cartesian to internal coordinates CLENMO.* cleans up $VEC groups There are files related to X windows graphics. See the file INTRO.MAN for their names. The remaining files are command language for the various machines. *.COM VAX command language. PROBE is especially useful for persons learning GAMESS. *.MVS IBM command language for MVS (dreaded JCL). *.CMS IBM command language for CMS. These should be copied to filetype EXEC. *.CSH UNIX C shell command language. These should have the "extension" omitted, and have their mode changed to executable. Names of source code modules The source code for GAMESS is divided into a number of sections, called modules, each of which does related things, and is a handy size to edit. The following is a list of the different modules, what they do, and notes on their machine dependencies. machine module description dependency ------- ------------------------- ---------- BASECP SBK and HW valence basis sets BASEXT DH, MC, 6-311G extended basis sets BASHUZ Huzinaga MINI/MIDI basis sets to Xe BASHZ2 Huzinaga MINI/MIDI basis sets Cs-Rn BASN21 N-21G basis sets BASN31 N-31G basis sets BASSTO STO-NG basis sets BLAS level 1 basic linear algebra subprograms CPHF coupled perturbed Hartree-Fock 1 CPROHF open shell/TCSCF CPHF 1 ECP pseudopotential integrals ECPHW Hay/Wadt effective core potentials ECPLIB initialization code for ECP ECPSBK Stevens/Basch/Krauss/Jasien/Cundari ECPs EIGEN Givens-Householder, Jacobi diagonalization EFDMY dummy source file FFIELD finite field polarizabilities FRFMT free format input scanner GAMESS main program, single point energy and energy gradient drivers, misc. GRD1 one electron gradient integrals GRD2A two electron gradient integrals 1 GRD2B " " " " GRD2C " " " " GRD2D " " " " GRD2E " " " " GRD2F " " " " GUESS initial orbital guess GUGDGA Davidson CI diagonalization 1 GUGDGB " " " 1 GUGDM 1 particle density matrix GUGDM2 2 particle density matrix 1 GUGDRT distinct row table generation GUGEM GUGA method energy matrix formation 1 GUGSRT sort transformed integrals 1 GVB generalized valence bond HF-SCF 1 (continued...) machine module description dependency ------- ------------------------- ---------- HESS hessian computation drivers HSS1A one electron hessian integrals HSS1B " " " " HSS2A two electron hessian integrals 1 HSS2B " " " " INPUTA read geometry, basis, symmetry, etc. INPUTB " " " " INPUTC " " " " INT1 one electron integrals INT2A two electron integrals 1 INT2B " " " INT2C roots for Rys polynomials IOLIB input/output routines,etc. 2 LAGRAN CI Lagrangian matrix 1 LOCAL various localization methods 1 MCSCF second order MCSCF calculation 1 MCTWO two electron terms for MCSCF 1 MP2 2nd order Moller-Plesset 1 MPCDAT MOPAC parameterization MPCGRD MOPAC gradient MPCINT MOPAC integrals MPCMOL MOPAC molecule setup MPCMSC miscellaneous MOPAC routines MTHLIB printout, matrix math utilities 1 NAMEIO namelist I/O simulator ORDINT sort atomic integrals 1 PARLEY communicate to other programs PRPEL electrostatic properties PRPLIB miscellaneous properties PRPPOP population properties RHFUHF RHF, UHF, and ROHF HF-SCF 1 RXNCRD intrinsic reaction coordinate SCFLIB HF-SCF utility routines, DIIS code SCRF self consistent reaction field SPNORB 1 e- spin-orbit coupling terms STATPT geometry and transition state finder STUB small version dummy routines SYMORB orbital symmetry assignment SYMSLC " " " 1 TCGSTB stub routines to link a serial GAMESS TRANS partial integral transformation 1 TRFDM2 backtransform 2 e- density matrix 1 TRNSTN CI transition moments TRUDGE nongradient optimization (continued...) machine module description dependency ------- ------------------------- ---------- UNPORT unportable, nasty code 3,4,5,6,7,8 VECTOR vectorized version routines 9 VIBANL normal coordinate analysis ZMATRX internal coordinates Ordinarily, you will not use STUB.SRC, which is linked only if your system has a very small amount of physical memory. In addition, the IBM mainframe version uses the following assembler language routines: ZDATE.ASM, ZTIME.ASM. UNIX versions may use the C code: ZMIPS.C, ZUNIX.C. The machine dependencies noted above are: 1) packing/unpacking 2) OPEN/CLOSE statments 3) machine specification 4) fix total dynamic memory 5) subroutine walkback 6) error handling calls 7) timing calls 8) LOGAND function 9) vector library calls Programming Conventions The following "rules" should be adhered to in making changes in GAMESS. These rules are important in maintaining portability, and should be strictly adhered to. Rule 1. If there is a way to do it that works on all computers, do it that way. Commenting out statements for the different types of computers should be your last resort. If it is necessary to add lines specific to your computer, PUT IN CODE FOR ALL OTHER SUPPORTED MACHINES. Even if you don't have access to all the types of supported hardware, you can look at the other machine specific examples found in GAMESS, or ask for help from someone who does understand the various machines. If a module does not already contain some machine specific statements (see the above list) be especially reluctant to introduce dependencies. Rule 2. a) Use IMPLICIT DOUBLE PRECISION(A-H,O-Z) specification statements throughout. b) All floating point constants should be entered as if they were in double precision. The constants should contain a decimal point and a signed two digit exponent. A legal constant is 1.234D-02. Illegal examples are 1D+00, 5.0E+00, and 3.0D-2. c) Double precision BLAS names are used throughout, for example DDOT instead of SDOT. The source code activator ACTVTE will automatically convert these double precision constructs into the correct single precision expressions for machines that have 64 rather than 32 bit words. Rule 3. FORTRAN 77 allows the use of generic functions. Thus the routine SQRT should be used in place of DSQRT, as this will automatically be given the correct precision by the compilers. Use ABS, COS, INT, etc. Your compiler manual will tell you all the generic names. Rule 4. Every routine in GAMESS begins with a card containing the name of the module and the routine. An example is "C*MODULE xxxxxx *DECK yyyyyy". The second star is in column 18. Here, xxxxxx is the name of the module, and yyyyyy is the name of the routine. Furthermore, the individual decks yyyyyy are stored in alphabetical order. This rule is designed to make it easier for a person completely unfamiliar with GAMESS to find routines. The trade off for this is that the driver for a particular module is often found somewhere in the middle of that module. Rule 5. Whenever a change is made to a module, this should be recorded at the top of the module. The information required is the date, initials of the person making the change, and a terse summary of the change. Rule 6. No lower case characters, no more than 6 letter variable names, no imbedded tabs, statements must lie between columns 7 and 72, etc. In other words, old style syntax. * * * The next few "rules" are not adhered to in all sections of GAMESS. Nonetheless they should be followed as much as possible, whether you are writing new code, or modifying an old section. Rule 7. Stick to the FORTRAN naming convention for integer (I-N) and floating point variables (A-H,O-Z). If you've ever worked with a program that didn't obey this, you'll understand why. Rule 8. Always use a dynamic memory allocation routine that calls the real routine. A good name for the memory routine is to replace the last letter of the real routine with the letter M for memory. Rule 9. All the usual good programming techniques, such as indented DO loops ending on CONTINUEs, IF-THEN-ELSE where this is clearer, 3 digit statement labels in ascending order, no three branch GO TO's, descriptive variable names, 4 digit FORMATs, etc, etc. The next set of rules relates to coding practices which are necessary for the parallel version of GAMESS to function sensibly. They must be followed without exception! Rule 10. All open, rewind, and close operations on sequential files must be performed with the subroutines SEQOPN, SEQREW, and SEQCLO respectively. You can find these routines in IOLIB, they are easy to use. Rule 11. All READ and WRITE statements for the formatted files 5, 6, 7 (variables IR, IW, IP, or named files INPUT, OUTPUT, PUNCH) must be performed only by the master task. Therefore, these statements must be enclosed in "IF (MASWRK) THEN" clauses. The MASWRK variable is found in the /PAR/ common block, and is true on the master process only. This avoids duplicate output from slave processes. At the present time, all other disk files in GAMESS also obey this rule. Rule 12. All error termination is done by means of "CALL ABRT" rather than a STOP statement. Since this subroutine never returns, it is OK to follow it with a STOP statement, as compilers may not be happy without a STOP as the final executable statment in a routine. Parallel version of GAMESS Under the auspices of a joint ARPA and Air Force project, GAMESS has begun the arduous journey toward parallelization. Currently, nearly all ab initio methods run in parallel, although many of these still have a step or two running sequentially only. Only MP2 for UHF/ROHF has no parallel method coded. In addition, MOPAC runs can be run on one node only. More information about the parallel implementation is given below, after the directions for installation and execution. If a parallel linked version of GAMESS is run on only one node, it behaves as if it is a sequential version, and the full functionality of the program is available to you. * * * The two major philosophies for distributed memory MIMD (multiple instruction on multiple data) parallel programs are 1) Have a master program running on one node do all of the work, except that smaller slave programs running on the other nodes are called to do their part of the compute intensive tasks, or 2) Have a single program duplicate all work except for compute intensive code where each node does only its separate piece of the work (SPMD, which means single program, multiple data). We have chosen to implement the SPMD philosophy in GAMESS for several reasons. The first of these is that only one code is required (not master and slave codes). Therefore, two separate GAMESS codes do not need to be maintained. The second reason is also related to maintainance. GAMESS is constantly evolving as new code is incorporated into it. The parallel calls are "hidden" at the lowest possible subroutine levels to allow programmers to add their code with a minimum of extra effort to parallelize it. Therefore, new algorithms or methods are available to all nodes. The final reason given here is that duplication of computation generally cuts down on communication. The only portion of the master/slave concept to survive in GAMESS is that the first process (node 0) handles reading all input lines and does all print out and PUNCH file output, as well as all I/O to the DICTNRY master file. In this sense node 0 is a "master". A reminder here to all programmers: you should STRICTLY obey the rules for programming laid out in the Programming Conventions Section of this manual; especially the ones involving MASWRK in I/O statements! * * * Several tools are available for parallelization of codes. We have chosen to use the parallelization tool TCGMSG from Robert Harrison, now at Pacific Northwest Laboratory. This message passing toolkit has been ported to many UNIX machines and was written specifically for computational chemistry. It works on distributed memory MIMD systems, on Ethernetworks of ordinary workstations, and on shared memory parallel computers. Thus TCGMSG allows one to run parallel GAMESS on a fairly wide assortment of hardware. Be sure to note that TCGMSG does support communication between Ethernet workstations of different brands and/or speeds. For example, we have been able to run on a 3 node parallel system built from a DECstation, a SGI Iris, and a IBM RS/6000! (see XDR in $SYSTEM.) It is also useful to note that your Ethernet parallel system does not have to contain a power of two number of nodes. TCGMSG uses the best interprocess communication available on the hardware being used. For a Ethernetwork of workstations, this means that TCP/IP sockets are used for communication. In turn, this means it is extremely unlikely you will be able to include non-Unix systems in a Ethernet parallel system. * * * If you are trying to run on a genuine parallel system on which TCGMSG does not work, you may still be in luck. The "stubs" TCGSTB.SRC can be used to translate from the TCGSMG calls sprinkled throughout GAMESS to some other message passing language. For example, we are able to use GAMESS on the IBM SP1, Intel Paragon, and Thinking Machines CM-5 in this way, so there is no need to install TCGMSG to run GAMESS on these systems. * * * Our experience with parallel GAMESS is that it is quite robust in production runs. In other words, most of the grief comes during the installation phase! TCGMSG will install and execute without any special priviledges. The first step in getting GAMESS to run in parallel is to link GAMESS in sequential mode, against the object file from TCGSTB.SRC, and ensure that the program is working correctly in sequential mode. Next, obtain a copy of the TCGMSG toolkit. This is available by anonymous ftp from ftp.tcg.anl.gov. Go to the directory /pub/tcgmsg and, using binary mode, transfer the file tcgmsg.4.04.tar.Z. (or higher version) Unpack this file with 'uncompress' and 'tar -xvf'. The only modification we make to TCGMSG before compiling it is to remove all -DEVENTLOG flags from the prototype file tcgmsg/ipcv4.0/Makefile.proto. Then, use the makefile provided to build the TCGMSG library chdir ~/tcgmsg make all MACHINE=IBMNOEXT If your machine is not a IBM RS/6000, substitute the name of your machine instead. At this point you should try the simple "hello" example, chdir ipcv4.0 parallel hello to make sure TCGMSG is working. Finally, link GAMESS against the libtcgmsg.a library instead of tcgstb.o to produce a parallel executable for GAMESS. It is not necessary to recompile to accomplish this. Instead just change the 'lked' script and relink. * * * Execute GAMESS by modifying the 'pargms' script to invoke the TCGMSG program 'parallel', according to the directions within that script. You also must create a 'gamess.p' file in your home directory,such as # user, host, nproc, executable, workdir theresa si.fi.ameslab.gov 1 /u/theresa/gamess/gamess.01.x /scr/theresa windus ge.fi.ameslab.gov 1 /u/windus/gamess/gamess.01.x /wrk/windus The fields in each line are: username on that machine, hostname of that machine, number of processes to be run on that machine, full file name of the GAMESS executable on that machine, and working directory on that machine. Comments begin with a # character. Although TCGMSG allows long lines to continue on to a new line, as shown above, you should not do this. The execution script provided with GAMESS will automatically delete work files established in the temporary directories, but only if this script gives all host info on a single line. A detailed explanation of each field follows: The first hostname given must be the name of the machine on which you run the 'pargms' script. This script defines environment variables specifying the location of the input and output files. The environment is not passed to other nodes by TCGMSG's "parallel" program, so the master process (node 0) running "pargms" **must** be the first line of your gamess.p file. The hostname may need to be the shortened form, rather than the full dotted name, especially on SGI and Unicos. In general, the correct choice is whatever the response to executing the command "hostname" is. The processes on other workstations are generated by use of the Unix 'rsh' command. This means that you must set up a .rhosts file in your home directory on each node on which you intend to run in parallel. This file validates login permission between the various machines, by mapping your accounts on one machine onto the others. For example, the following .rhosts file might be in Theresa's home directory on both systems, si.fi.ameslab.gov theresa ge.fi.ameslab.gov windus You can test this by getting 'rsh' to work, by a command such as this, (from si.fi.ameslab.gov) rsh ge.fi.ameslab.gov -l windus 'df' and then also try it in the reverse direction too. Note that the number of processes to be started on a given machine is ordinarily one. The only exception is if you are running on a multiCPU box, with a common memory. In this case, gamess.p should contain just one line, starting n processes on your n CPUs. This will used shared memory communications rather than sockets to pass messages, and is more efficient. The executable file does not have to be duplicated on every node, although as shown in the example it can be. If you have a homogenous Ethernet system, and there is a single file server, the executable can be stored on this server to be read by the other nodes by NFS. Of course, if you have a heterogenous network, you must build a separate executable for each different brand of computer you have. At present GAMESS may write various binary files to the working directory, depending on what kind of run you are doing. In fact, the only type of run which will not open files on the other nodes is a direct SCF, non-analytic hessian job. Any core dump your job might produce will end up in this work directory as well. * * * We have provided you with a script named 'seqgms' which will run a parallel-linked version of GAMESS using only one process on your current machine. Seqgms will automatically build a single node .p file. Using this script means you need to keep only a parallel-linked GAMESS executable, and yet you still retain access to the parts of GAMESS that do not yet run in parallel. * * * We turn now to a description of the way each major parallel section of GAMESS is implemented, and give some suggestions for efficient usage. * * * The HF wavefunctions can be evaluated in parallel using either conventional disk storage of the integrals, or via direct recomputation of the integrals. Assuming the I/O speed of your system is good, direct SCF is *always* slower than disk storage. But, a direct SCF might be faster if your nodes access disk via NFS over the Ethernet, or if you are running on a Intel or CM-5 machine. But, if you are running on Ethernetted workstations which have large local disks on each one, then conventional disk based SCF is probably fastest. When you run a disk based SCF in parallel, the integral files are opened in the work directory which you defined in your gamess.p file. Only the subset of integrals computed by each node are stored on that node's disk space. This lets you store integral files (in pieces) that are larger than will fit on any one of your computers. You may wish to experiment with both options, so that you learn which is fastest on your hardware setup. * * * One of the most important issues in parallelization is load balancing. Currently, GAMESS has two algorithms available for load balancing of the two-electron integrals and gradients. The first is a simple inner loop algorithm (BALTYP=LOOP). The work of the inner most loop is split up so the next processor works on the next loop occurence. If all processors are of the same speed and none of the processors is dedicated to other work (for example, an Intel), this is the most effective load balance technique. The second method is designed for systems where the processor speeds may not be the same, or where some of the processors are doing other work (such as a system of equal workstations in which one of them might be doing other things). In this technique, as soon as a processor finishes its previous task, it takes the next task on the list of work to be done. Thus, a faster node can take more of the work, allowing all nodes to finish the run at the same time. This method is implemented throughout most of GAMESS (see BALTYP=NXTVAL in $SYSTEM). It requires some extra work coordinating which tasks have been done already, so NXTVAL adds a communication penalty of about 5% to the total run time. All integral sections (meaning the ordinary integrals, gradient integrals, and hessian integrals) have both LOOP and NXTVAL balancing implemented. Thus all of a HF level run involving only the energy and gradient has both load balancing techniques. Analytic HF hessians also have both balancing techniques for the integral transformation step. The parallel CI/MCSCF program also contains both balancing algorithms, except that for technical reasons MCSCF gradient computation will internally switch to the LOOP balancing method for that step only. The parallel MP2 program uses only LOOP balancing during the MP2, although it will use either balancing method during the preliminary SCF. The IBM SP1, Intel, CM-5 always use LOOP balancing, ignoring your input BALTYP. * * * You can find performance numbers for conventional and direct SCF, as well as gradient evaluation in the paper M.W.Schmidt, et al., J.Comput.Chem. 14, 1347-1363(1993). Data for the MCSCF program is not yet published, so we will include one example here. The data are from IBM RS/6000 model 350s, connected by Ethernet, using LOOP balancing. CPU times to do one iteration are in seconds: # CPUs= 1 2 3 4 5 - - - - - MO guess 3.8 4.1 5.3 5.2 5.1 AO ints 391.9 392.0 391.5 391.0 391.0 DRT 0.5 0.5 0.6 0.6 0.6 transf 1539.1 764.5 616.2 461.0 304.7 CI 1.4 0.9 0.8 0.7 0.6 DM2 0.1 0.1 0.2 0.2 0.2 Lag+Hess 16.6 20.6 26.8 26.3 25.3 NR 25.2 27.0 25.4 25.4 25.4 The first three steps precede the MCSCF iterations and are not parallel. The integral transformation, and generation of the CI Hamiltonian and its diagonalization are reasonably parallel (the above example has a trivial number of CSFs). Large global sums overwhelm the parallel construction of the Lagrangian and orbital Hessian. At present the Newton-Raphson orbital change is running sequentially. Not shown: The backtransform of the DM2 to the AO basis to set up gradient calculation runs close to sequentially, but the gradient integral computation is perfectly parallel. A CI/MCSCF job will open several disk files on each node. For example, if the integral transformation is not being run in direct mode (see DIRTRF in $TRANS) then each node will compute and store a full copy of the AO integrals. Each node will store a subset of the transformed integrals, the CI Hamiltonian, and the density matrix. The algorithm thus demands not only disk storage on each node, but also a reasonable I/O bandwidth. We have not had the opportunity to run the MCSCF code on an Intel Paragon or a Thinking Machines CM-5, which are not known for their I/O capacity. Similar comments apply to analytic hessians: you must have disk storage on each node, reachable at a reasonable bandwidth. The integral transformation just described is also used to drive both parallel analytic hessians and energy localizations. Thus the scalability of parallel hessians is much better than described by T.L.Windus, M.W.Schmidt, M.S.Gordon, Chem.Phys.Lett., 216, 375-379(1993), in that all steps but the coupled Hartree-Fock are now parallel. The closed shell parallel MP2 computation is adapted from Michel Dupuis' implementation. In contrast to the usual transformation, the specialized MP2 transformation has the AO integrals actually distributed over each node, instead of being replicated on each. Obviously this uses much less disk storage! However, since each node needs to work with the full AO integral list, the subset stored on each node must be broadcast to all other nodes. Thus the savings in disk storage comes at the expense of substantial extra communication. Initial tests show that the extra communications prevent the MP2 code from scaling very well when Ethernet (a rather slow communication channel) is used to tie together workstations. We do not yet have any information about the code's performance on a machine such as the IBM SP1 with fast communications. To summarize, the normal transformation (used by CI, MCSCF, energy localization, analytic hessians) must store duplicate lists of AO integrals on each node, but has almost no internode communication, and thus scales well on even low speed networks. The MP2 transformation stores only a subset of AO integrals on each node, but requires high speed communications to send each integral to all nodes. Time will tell us which method is wiser. Note that both of the transformations distribute the memory needs, which can be substantial on one node, over all the nodes. Both methods must evaluate the full AO integral list if a direct integral transformation is done, during each pass. Being able to distribute the memory (i.e. the passes) over each nodes means that direct transformations make more sense in parallel than in sequential mode. In fact, each node may only need to compute the AO integrals once, instead of many times if the job is run on one node. Note that both direct transforms compute the full AO integral list on each node during each pass, a blatant sequential bottleneck. All types of ab initio runs (except for UHF/ROHF MP2 energies) should now run in parallel. However, only the code for HF energies and gradients is mature, so several sequential bottlenecks remain. The following steps of a parallel run will be conducted sequentially by the master: MCSCF: solution of Newton-Raphson equations analytic hessians: the coupled Hartree-Fock energy localizations: the orbital localization step transition moments/spin-orbit: the final property step However, all other steps (such as the evaluation of the underlying wavefunction) do speed up in parallel. Other steps which do not scale well, although they do speed up slightly are: HF: solution of SCF equations MCSCF/CI: Hamiltonian and 2 body density generation MCSCF: 2 body density back transformation Future versions of GAMESS will address these bottlenecks. In the meantime, some trial and error will teach you how many nodes can effectively contribute to any particular type of run. One example, using the same RS/6000-350 machines and molecule (bench12.inp converted to runtyp=hessian, with 2,000,000 words, with baltyp=loop) gives the following replacement for Table 1 of the Chem.Phys.Lett. 216, 375-379(1993) paper: p= 1 2 3 --- --- --- setup 0.57 0.69 0.73 1e- ints 1.10 0.87 0.88 huckel guess 15.77 15.74 16.17 2e- ints 111.19 55.34 37.42 RHF cycles 223.13 103.26 79.44 properties 2.23 2.46 2.63 2e- ints -- 111.28 110.97 transformation 1113.67 552.38 381.09 1e- hess ints 28.20 16.46 14.63 2e- hess ints 3322.92 1668.86 1113.37 CPHF 1438.66 1433.34 1477.32 ------- ------- ------- total CPU 6258.01 3961.34 3235.27 total wall 8623(73%) 5977(66%) 5136(63%) so you can see the CPHF is currently a hindrance to full scalability of the analytic hessian program. List of parallel broadcast numbers GAMESS uses TCGMSG calls to pass messages between the parallel processes. Every message is identified by a unique number, hence the following list of how the numbers are used at present. If you need to add to these, look at the existing code and use the following numbers as guidelines to make your decision. All broadcast numbers must be between 1 and 32767. 20 : Parallel timing 100 - 199 : DICTNRY file reads 200 - 204 : Restart info from the DICTNRY file 210 - 214 : Pread 220 - 224 : PKread 225 : RAread 230 : SQread 250 - 265 : Nameio 275 - 310 : Free format 325 - 329 : $PROP group input 350 - 354 : $VEC group input 400 - 424 : $GRAD group input 425 - 449 : $HESS group input 450 - 474 : $DIPDR group input 475 - 499 : $VIB group input 500 - 599 : matrix utility routines 800 - 830 : Orbital symmetry 900 : ECP 1e- integrals 910 : 1e- integrals 920 - 975 : EF and SCRF integrals 980 - 999 : property integrals 1000 - 1025 : SCF wavefunctions 1050 : Coulomb integrals 1200 - 1215 : MP2 1300 : localization 1500 : One-electron gradients 1505 - 1599 : EF and SCRF gradients 1600 - 1602 : Two-electron gradients 1605 - 1615 : One-electron hessians 1650 - 1665 : Two-electron hessians 1700 : integral transformation 1800 : GUGA sorting 1850 - 1865 : GUGA CI diagonalization 1900 - 1905 : GUGA DM2 generation 2000 - 2010 : MCSCF 2100 - 2120 : coupled perturbed HF Disk files used by GAMESS unit name contents ---- ---- -------- 4 IRCDATA archive results punched by IRC runs, and restart data for numerical HESSIAN runs. 5 INPUT Namelist input file. This MUST be a disk file, as GAMESS rewinds this file often. 6 OUTPUT Print output (FT06F001 on IBM mainframes) If not defined, UNIX systems will use the standard output for this printout. 7 PUNCH Punch output. A copy of the $DATA deck, orbitals for every geometry calculated, hessian matrix, normal modes from FORCE, properties output, IRC restart data, etc. 8 AOINTS Two e- integrals in AO basis 9 MOINTS Two e- integrals in MO basis 10 DICTNRY Master dictionary, for contents see below. 11 DRTFILE Distinct row table file for -CI- or -MCSCF- 12 CIVECTR Eigenvector file for -CI- or -MCSCF- 13 NTNFMLA Newton-Raphson formula tape for -MCSCF- 14 CIINTS Sorted integrals for -CI- or -MCSCF- 15 WORK15 GUGA loops for diagonal elements; ordered second order density matrix; scratch storage during Davidson diag 16 WORK16 GUGA loops for off diagonal elements; unordered second order density matrix; 2nd order density in AO basis 17 CSFSAVE CSF data for transition moments, SOC 18 FOCKDER derivative Fock matrices analytic hess 20 DASORT Sort file for -MCSCF- or -CI-; also used by HF's DIIS method 23 JKFILE J and K "Fock" matrices for -GVB- 24 ORDINT sorted AO integrals 25 EFPIND effective fragment data Contents of the direct access file 'DICTNRY' 1. Atomic coordinates 2. various energy quantities in /ENRGYS/ 3. Gradient vector 4. Hessian (force constant) matrix int 5. ISO - symmetry operations for shells int 6. ISOC - symmetry operations for centers (atoms) 7. PTR - symmetry transformation for p orbitals 8. DTR - symmetry transformation for d orbitals 9. not used, reserved for FTR 10. not used, reserved for GTR 11. Bare nucleus Hamiltonian integrals 12. Overlap integrals 13. Kinetic energy integrals 14. Alpha Fock matrix (current) 15. Alpha orbitals 16. Alpha density matrix 17. Alpha energies or occupation numbers 18. Beta Fock matrix (current) 19. Beta orbitals 20. Beta density matrix 21. Beta energies or occupation numbers 22. Error function extrapolation table 23. Old alpha Fock matrix 24. Older alpha Fock matrix 25. Oldest alpha Fock matrix 26. Old beta Fock matrix 27. Older beta Fock matrix 28. Oldest beta Fock matrix 29. Vib 0 gradient for FORCE runs 30. Vib 0 alpha orbitals in FORCE 31. Vib 0 beta orbitals in FORCE 32. Vib 0 alpha density matrix in FORCE 33. Vib 0 beta density matrix in FORCE 34. dipole derivative tensor in FORCE. 35. frozen core Fock operator 36. Lagrangian multipliers 37. floating point part of common block /OPTGRD/ int 38. integer part of common block /OPTGRD/ 39. ZMAT of input internal coords int 40. IZMAT of input internal coords 41. B matrix of redundant internal coords 42. not used. 43. Force constant matrix in internal coordinates. 44. SALC transformation 45. symmetry adapted Q matrix 46. S matrix for symmetry coordinates 47. ZMAT for symmetry internal coords int 48. IZMAT for symmetry internal coords 49. B matrix 50. B inverse matrix 51. overlap matrix in Lowdin basis, temp Fock matrix storage for ROHF 52. genuine MOPAC overlap matrix 53. MOPAC repulsion integrals 54. Coulomb integrals 55-60. not used 61. temp MO storage for GVB and ROHF-MP2 62. temp density for GVB 63. dS/dx matrix for hessians 64. dS/dy matrix for hessians 65. dS/dz matrix for hessians 66. derivative hamiltonian for OS-TCSCF hessians 67. partially formed EG and EH for hessians 68. MCSCF first order density in MO basis 69. alpha Lowdin populations 70. beta Lowdin populations 71. alpha orbitals during localization 72. beta orbitals during localization 73-83. not used 84. d/dx dipole velocity integrals 85. d/dy dipole velocity integrals 86. d/dz dipole velocity integrals 87-88. reserved for effective fragment use 89. not used 90. ECP coefficients int 91. ECP labels 92. ECP coefficients int 93. ECP labels 94. bare nucleus Hamiltonian during FFIELD runs 95. x dipole integrals 96. y dipole integrals 97. z dipole integrals 98. former coords for Schlegel geometry search 99. former gradients for Schlegel geometry search In order to correctly pass data between different machine types when running in parallel, it is required that a DAF record must contain only floating point values, or only integer values. No logical or Hollerith data may be stored. The final calling argument to DAWRIT and DAREAD must be 0 or 1 to indicate floating point or integer values are involved. The records containing integers are so marked in the above list. Physical record 1 (containing the DAF directory) is written whenever a new record is added to the file. This is invisible to the programmer. The numbers shown above are "logical record numbers", and are the only thing that the programmer need be concerned with.