Running on a desktop

In a Jupyter notebook

import veloxchem as vlx

water_xyz_string = """
3
water
O  0.00000  0.00000  0.00000
H  0.00000  0.00000  1.79524
H  1.69319  0.00000 -0.59904
"""

molecule = vlx.Molecule.read_xyz_string(water_xyz_string)
basis = vlx.MolecularBasis.read(molecule, 'def2-svp')

scfdrv = vlx.ScfRestrictedDriver()
scfdrv.conv_thresh = 1.0e-6
scfdrv.xcfun = 'b3lyp'
scf_results = scfdrv.compute(molecule, basis)

A comprehensive presenation of how to interact and run the VeloxChem program in a Jupyter notebook is provided in the eChem book.

Using an input file

An input file driven VeloxChem calculation can be started on the command line as follows:

$ vlx water.inp [water.out]

If the optional output file name is omitted, the output will be sent to standard output.

The input file (here assumed to be named water.inp) consists of multiple groups marked with @group name and @end. For example, the following input file has three groups: jobs, method settings, and molecule. In the molecule group, the default unit for Cartesian coordinates is Angstrom.

@jobs
task: scf
@end

@method settings
xcfun: b3lyp
basis: def2-svp
@end

@molecule
charge: 0
multiplicity: 1
xyz:
O  0.00000  0.00000  0.00000
H  0.00000  0.00000  1.79524
H  1.69319  0.00000 -0.59904
@end