MOLPRO

4 GENERAL PROGRAM STRUCTURE 15
4.2 Files
MOLPRO uses three sequential text files, namely the input file, the output file, and the punch
file. The punch file is a short form of the output which contains the most important data and
results, such as geometries, energies, dipole moments, etc. The punch file can be processed
by the separate program READPUN, which selects specific results by keywords and is able to
produce ordered tables in user supplied format. Furthermore, there are up to 9 binary MOLPRO
files available, each one known to the program simply by its number (1 to 9). By default, they
are temporary files, usually allocated dynamically by the program, but they can be connected
to permanent files with the FILE command. Each file is direct access, and word addressable
(word=64 bit usually), but is organised in records of any length. The name, address and length
of each record is held in a directory at the start of the file.
File 1 is the main file, holding basis set, geometry, and the one and two electron integrals. By
default, file 2 is the dump file and used to store the wavefunction information, i.e. orbitals, CI
coefficients, and density matrices. File 3 is an auxiliary file which can be used in addition to file
2 for restart purposes. Often files 1 and 2 (and 3) are declared as permanent files (see FILE) to
enable restarts. Storing the wavefunction information on file 2 is useful, since the integral file is
overwritten at each new geometry, while the orbitals and CI coefficients of one calculation can
be used as a starting guess for the next calculation at a neighbouring geometry. Files 4 to 8 are
used as scratch space, e.g., for sorting the integrals, storage of transformed integrals and of the
CI vectors. These files should normally not be made permanent.
Note that the file name appearing in molpro input is always converted to lower case on unix
machines.
4.3 Records
Record names are positive integers, and are usually referred to in the format record.file, e.g.,
2100.2 means the record called 2100 on file 2. Note that these names are quite arbitrary, and
their numerical values have nothing to do with the order of the records in the file. Record names
≤ 2000 are reserved for standard quantities (e.g. integrals, properties etc.) and you should never
use these in an input, unless you know exactly what you are doing. Some important default
records to remember are
2100 RHF dump record (closed and open-shell)
2200 UHF dump record
2140 MCSCF dump record
4100 CPHF restart information
5000 MCSCF gradient information
5100 CP-MCSCF gradient information
5200 MP2 gradient information
5300 Hessian restart information
5400 Frequencies restart information
6300 Domain restart information
If an input contains several wavefunction calculations of the same type, e.g., several MCSCF
calculations with different active spaces, the record number will be increased by 1 for each
calculation of the same type. Thus, the results of the first SCF calculation in an input are stored