Skip to content

Property

This document concerns objects corresponding to calculations of molecular properties for a single geometry. Such calculations include population analysis, Fukui indices of reactivity, and NMR properties.

The input for performing a Property calculation is created via the PropertyInput object, which requires the same fields as in EnergyInput and a properties field for specifying a list of property types. In addition, we can also specify additional detail parameters for the property computations in property_details.

Currently, the supported property types are:

  • population
  • fukui
  • nmr (only available at the DFT level of theory)

The results of a PropertyInput calculation are stored in the PropertyResult object.

Example

The following examples demonstrate how to perform properties calculations:

import sierra
from sierra.inputs import *

water = Molecule(pubchem="water")

# Perform population analysis for water at GFN1-xTB level of theory
xtb_prop_inp = PropertyInput(
    molecule=water, method=XTBMethod(model="GFN1"), properties=["population"]
)
xtb_prop_result = sierra.run(xtb_prop_inp)
xtb_population = xtb_prop_result.population
print("Partial charges on each atom:")
#> Partial charges on each atom:
print(xtb_population.charges)
#> [-0.66546322  0.33273156  0.33273166]


# Compute NMR shielding for water at DFT B3LYP/Def2-SVP level of theory
dft_prop_inp = PropertyInput(
    molecule=water,
    method=DFTMethod(ao="def2-svp", xc="B3LYP"),
    properties=["nmr"],
)
dft_prop_result = sierra.run(dft_prop_inp)
nmr_property = dft_prop_result.nmr
print("NMR isotropic shielding on each nucleus:")
#> NMR isotropic shielding on each nucleus:
print(nmr_property.isotropic_shielding)
"""
{
    1: 0.00033809310743096867,
    2: 3.134494761887655e-05,
    3: 3.134493457300241e-05,
}
"""

PropertyInput

Fields

All the fields in EnergyInput and the following:

properties

A list of property types to compute with the given method

  • Type: List[PropertiesEnum]
  • Default: [PropertiesEnum.population]
property_details
Additional detail parameters to pass to the property computations

PropertyResult

Fields

All the fields in PropertyInput, EnergyResult and the following:

fukui

The computed atom-resolved Fukui reactivity indices.

nmr

The nuclear magnetic resonance (NMR) properties.

population

The computed population analysis.