Charge Fitting
- class ChargeFitting
Charge fitting calculations can be carried out using the ChargeFitting()
driver, which
expects a QM-level Theory object, e.g.:
my_frag = Fragment(coords='my_frag.xyz')
my_theory = GAMESS_UK(frag=my_frag,
method='dft',
functional='b3lyp',
basis='6-31g*')
my_fit1 = ChargeFitting(theory=my_theory,
npoints=2400,
type='shell',
vdw_scale=1.5,
nlayers=2,
vdw_incr=0.2)
The charge fitting calculation is run with:
my_job.run(dryrun=False)
Then the resulting charges will be stored in my_frag.charges
(see: <class Fragment>).
Methods
- ChargeFitting.run()
Options
The single-point driver takes the following arguments:
- alpha
(default:
1.0
) Search direction
- constraints
(default:
[]
) Constraint definition
- frozen
(default:
[]
) A list of indices of atoms to freeze
- initial
(default:
float('nan')
) Initial values of charges
- maxcycles
(default:
10000
) Maximum cylces of iterations
- maxinners
(default:
10
) Maximum cycles of inner iterations
- method
Allowed values: *
'resp'
: (default) Kolllman’s restrained electrostatic potential (RESP). See: C. I. Bayly, et al., J. Phys. Chem. 1993, 97, 10269
- nlayers
(default:
4
) Number of layers of grid points
- npoints
(default:
200*theory.frag.natoms
) Number of grid points to generate
- tol_inner
(default:
1.0E-5
) Tolerance of convergence for inner iterations
- tolerance
(default:
1.0E-12
) Tolerance of convergence
- type
Allowed values: *
'shell'
: (default) Uses shell-like grid points
- vdw_scale
(default:
1.2
) van der Waals scale
- vdw_incr
(default:
0.2
) Increment of van der Waals :0.4/nlayers**0.5