Skip to content

Latest commit

 

History

History
98 lines (80 loc) · 3.63 KB

README.md

File metadata and controls

98 lines (80 loc) · 3.63 KB
Raw

Short Description

The DLFIND manual is attached. For convenience, a non-exhaustive list of default parameter values is provided here. The "under-the-hood" algorithms for choosing default parameters are in some cases more complicated than those presented here: e.g., multistate optimizations sometimes change defaults relative to their single-state congeners.

printl

Printout level.

  • 0: none
  • 2: some (default)
  • 4: verbose
  • 6: debug

icoord

Type of coordinate system.

  • 0: Cartesian (default)
  • 1: hybrid delocalized internal coordinates, primitive internal coordinate scheme
  • 2: hybrid delocalized internal coordinates, total connection scheme
  • 3: delocalized internal coordinates, primitive internal coordinate scheme
  • 4: delocalized internal coordinates, total connection scheme
  • 10–14: Lagrange–Newton conical intersection search, with 2nd digit referring to above options
  • 100+: nudged elastic band, quantum TS search, dimer method, chain search (see DLFIND manual).

iopt

Controls optimization algorithm.

  • 0: steepest descent
  • 1: Polak-Ribiere conjugate gradient w/ automatic restart
  • 2: Polak-Ribiere conjugate gradient w/ restart every 10 steps
  • 3: L-BGFS (default)
  • 10: P-RFO, for transition state searches

iline

Type of line search or trust radius.

  • 0: simple scaling (default for iopt > 3)
  • 1: trust radius based on energy criterion (default when iopt is 3)
  • 2: trust radius based on gradient criterion (default when iopt is 0, 1, or 2)

imultistate

Multistate calculations.

  • 0: single-state calculation (default)
  • 1: conical intersection optimization w/ penalty function algorithm
  • 2: conical intersection optimization w/ gradient projection algorithm
  • 3: conical intersection optimization w/ Lagrange–Newton algorithm

imicroiterations

Microiterative optimization for multilayer systems. Layers assigned via spec.

  • 0: standard (non-microiterative) optimization (default)
  • 1: microiterative optimization

inithessian

Method used to generate initial Hessian matrix.

  • 0: external calculation using dlf_get_hessian (default if dlf_get_hessian defined)
  • 1: build with one-point finite difference of gradient
  • 2: build with two-point finite difference of gradient (default otherwise)
  • 3: build diagonal Hessian with one-point finite difference
  • 4: set Hessian to be an identity matrix

update

How the Hessian is updated.

  • 0: no update
  • 1: Powell update
  • 2: Bofill update (default)
  • 3: BGFS update

tolerance

Convergence criterion on max gradient component. Default is 4.5E-4.

tolerance_e

Convergence criterion on max energy change. Default is 1E-6.

maxcycle

Max number of cycles. Default is 100.

lbgfs_mem

Memory for L-BGFS algorithm. Defaults to nvarin, with min value 5 and max value 50.

maxupd

Max number of Hessian updates. Default is 50.

maxstep

Maximum stepsize (in internal coordinates). Default is 0.5.

delta

Delta for finite-difference Hessian calculations (in internal coordinates). Default is 0.01.

spec

Freezing atoms, etc for optimization. (spec is an array with an entry for each atom.)

  • >0: active, treated normally. The value can be used to encode residue/fragment number.
  • 0: active in optimization, but treated in Cartesian coordinates no matter what.
  • -1: frozen
  • -2: x-coordinate frozen
  • -3: y-coordinate frozen
  • -4: z-coordinate frozen
  • -23: x-coordinate and y-coordinate frozen
  • -24: x-coordinate and z-coordinate frozen
  • -34: y-coordinate and z-coordinate frozen

spec also contains a way to specify constraints. See manual for more information.