NMR, IR, and Raman

NMR Shielding

Request NMR shielding with the nmr modifier.

.oqp:

hf/sto-3g
energy
nmr(gauge=cgo)
geom="h2o.xyz"

Python:

from oqp.openqp import OpenQP

job = OpenQP("h2o_nmr", silent=1)
job.molecule(geometry="water", charge=0, multiplicity=1)
job.theory.hf(basis="sto-3g")
job.workflow.nmr(gauge="cgo")

mol = job.run()

Legacy .inp:

[input]
runtype=energy
method=hf
basis=sto-3g

[scf]
type=rhf
multiplicity=1

[properties]
scf_prop=nmr
nmr_gauge=cgo

Runnable .oqp: examples/NMR/H2O_RHF-NMR.oqp. The same-stem .inp file is retained for legacy use.

nmr_gauge accepts:

Value	Meaning
cgo	Common-gauge-origin shielding.
giao	Gauge-including atomic orbital shielding where supported.

job.workflow.nmr(...) requires an HF/DFT reference-SCF theory. CGO NMR is limited to closed-shell RHF; use gauge="giao" for open-shell UHF/ROHF references. The helper also blocks range-separated and meta-GGA functionals for NMR because those paths are not implemented.

IR and Raman

IR and Raman intensities are produced from supported Hessian/frequency workflows. See Hessian and Frequencies for the main Hessian workflow page.

.oqp:

dft/bhhlyp/6-31g*
hess(S0,type=analytical)
ir
raman
geom="h2o.xyz"

Python:

from oqp.openqp import OpenQP

job = OpenQP("h2o_freq", silent=1)
job.molecule(geometry="water", charge=0, multiplicity=1)
job.theory.dft(functional="bhhlyp", basis="6-31g*")
job.workflow.hessian(type="analytical", state=0)

mol = job.run()

Legacy .inp:

[input]
runtype=hess
method=hf
functional=bhhlyp
basis=6-31g*

[hess]
type=analytical
state=0

Runnable .oqp inputs:

• examples/HESS/H2O_RHF-DFT_ANA_HESS.oqp
• examples/HESS/H2O_RHF-DFT_NUM_HESS.oqp

Each has a same-stem legacy .inp companion.