Skip to content

neb controls in .oqp

.oqp control reference

Use canonical routes and controls in input files. Raw names identify implementation storage. A control without an accepted canonical spelling is not available in .oqp files.

The neb section defines the product endpoint and image count for nudged elastic band calculations. Use it with input.runtype=neb. All native NEB algorithm controls live in oqp; concise .oqp input routes them there automatically.

Keywords

product

Use the physical route or primary calculation for this control; see the canonical spelling and ownership. Do not write this raw storage key as a separate input section.

Field Value
Type string
Default empty
Used by NEB product endpoint

Path to the product endpoint XYZ file. The reactant geometry comes from input.system; the product geometry comes from product.

Example:

hf/6-31g* neb(product="HCN_RHF-DFT_NEB_OQP_product.xyz",images=7)
geom="reactant.xyz"

nimage

Use the physical route or primary calculation for this control; see the canonical spelling and ownership. Do not write this raw storage key as a separate input section.

Field Value
Type integer
Default 5
Used by NEB image count

Number of NEB images. The input checker requires at least 3.

For concise input, write the endpoint and native controls together:

dft/pbe0/def2-svp neb(S0,product="product.xyz",images=7,output="path.xyz")
geom="reactant.xyz"

The concise images spelling lowers to nimage, and output lowers to oqp.neb_output.

The remaining six raw keys describe the optional geomeTRIC API backend. Concise .oqp rejects them and uses native spring, fmax, frms, boolean climb, align, and opt_ends instead. The native replacements have different semantics or units, so old values should not be copied mechanically.

k

Field Value
Type float
Default 1.0
Used by legacy geomeTRIC NEB spring strength

maxg

Field Value
Type float
Default 0.1
Used by legacy geomeTRIC NEB maximum-gradient convergence

avgg

Field Value
Type float
Default 0.05
Used by legacy geomeTRIC NEB average-gradient convergence

climb

Field Value
Type float
Default 0.5
Used by legacy geomeTRIC NEB climbing threshold

This float is distinct from the boolean oqp.climb used by native NEB.

align

Field Value
Type boolean
Default True
Used by legacy geomeTRIC NEB image alignment

optep

Field Value
Type boolean
Default False
Used by legacy geomeTRIC NEB endpoint optimization

Scientific references

Geometry optimization and reaction paths.