GAMESS-UK

class GAMESS_UK

This interface supports energy and gradient evaluations with the GAMESS-UK electronic structure package (v8, revision 6325 or later)

As a QM interface, the options described in QM interfaces are available, as well as the GAMESS-UK specific options outlined below.

A GAMESS-UK Theory object can be specified as follows:

my_frag = Fragment(...)

my_theory = GAMESS_UK(frag=my_frag,
                      method='hf',
                      basis='3-21g',
                      ...)

which would then be called as theory=my_theory in subsequent tasks (see Tasks).

General options

memory: (default: 52000000) Main memory request in words (8 bytes)

harmonic

Allowed values:

False: (default) Do not use spherical harmonic basis functions (as opposed to Cartesians)

True: Use spherical harmonic basis functions (as opposed to Cartesians)

SCF options

direct

Allowed values:

False: (default) Switch off direct

True: Request direct evaluation for a given wavefunction. For open shell systems the SCF type must be specified with scftype=, as the default scft direct only supports the RHF closed-shell wavefunction.

maxiter: (default: 50) Maximum number of SCF cycles permitted

scf_threshold: (default: 5) SCF convergence threshold 10E-scf_threshold.

newscf: (default: '') Free text input for newscf directives: can be either Python multi-line string (such as '''...''') or a filename (e.g., 'my_newscf.txt') of plain text containing multi-line string.