Section IRC

This section contains general information about the IRC (Intrinsic Reaction Coordinate) calculation. Details of the computed reaction path are in sections IRC_Forward and IRC_Backward.

atmcrd

ZMAT is a Z-matrix structure (connection matrix) is available. CART otherwise

geocrd

CART or ZMAT: the type of coordinates to change, optimize and trace

PointStatus

A string status variable of the current IRC point. Value can be 'DONE' (if the point has been computed), 'EXEC' if its computation has not yet finished.

nfree

Number of optimization coordinates that can be varied. See section GeoOpt

idfree

(3,natoms) pointers to the optimization variables for each of the atomic coordinates. A zero means: frozen by constraint

xyz

Cartesian coordinates

kmatrix

Connection matrix, if a Z-matrix structure is available

zmatrix

Internal coordinates

Energies

Energy at the Transition State

Dipole

Dipole moment at the Transition State

Gradients

Computed energy gradients at the (assumed) Transition State (should be very small)

AtomCharge Mulliken

Mulliken atomic charges, for the TS geometry

AtomSpinDen Mulliken

Atomic spin densities (Mulliken) at the TS

AtomCharge_initial Voronoi

Voronoi atomic charges at the TS, from the sum-of-fragments density

AtomCharge_SCF Voronoi

Similar, for the SCF density

modtrc

Defines the start direction for the IRC path. A positive value n selects the n-th eigenvector of the Hessian. A value -1 selects the gradient vector (which must then, of course, not be exactly zero). A value -2 specifies that the start direction is specified in the input file.

step

Step length (in mass-weighted metric) between successive points of the IRC path.

stepMin

The minimum value for the step

stepMax

The maximum value for the step

Hessian inverted_ZMAT

Inverse Hessian in internal coordinates.

lfree

The number of independent optimization step directions (for the restricted optimization orthogonal to the IRC path.

vfree

Direction vectors (3,natoms,lfree) for the independent optimization directions

GradientVector

The current gradient vector (during optimization)