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[hess]

The [hess] section controls Hessian, frequency, and thermochemistry workflows.

Keywords

type

Field Value
Type string
Default numerical
Values numerical, analytical
Used by Hessian dispatch

Selects numerical finite-difference or native analytical Hessian dispatch. Analytical Hessians are validated for supported HF/DFT ground-state cases. The input checker requests type=numerical when the method, state, or basis is outside the analytical path.

state

Field Value
Type integer
Default 0
Used by Hessian target state

HF/DFT Hessians use state 0. TDHF-family Hessian workflows use positive excited-state indices.

dx

Field Value
Type float
Default 0.01
Used by numerical Hessian displacement

Finite-difference step size for numerical Hessians.

nproc

Field Value
Type integer
Default 1
Used by numerical Hessian workers

Worker count for numerical Hessian calculations. Must be at least 1.

read

Field Value
Type boolean
Default False
Used by Hessian restart/input

Reads an existing Hessian where the workflow supports it.

restart

Field Value
Type boolean
Default False
Used by numerical Hessian restart

Continues an interrupted numerical Hessian workflow.

temperature

Field Value
Type float list
Default 298.15
Used by thermochemistry

Temperature or temperatures, in Kelvin, for thermochemical analysis. Values must be positive.

clean

Field Value
Type boolean
Default False
Used by temporary Hessian files

Removes temporary Hessian files where supported.