scfguess

This option defines the arguments for searching minimum energy crossing point (MECP).

num_steps

Value	An integer
Default	200

The maximum number of MECP search.

energy_cov

Value	A real number
Default	1.E-5

The energy difference convergence threshold. When energy_cov, grad_cov, and dr_cov are all met, the MECP will be set to be converged.

grad_cov

Value	A real number
Default	1.E-3

The gradient convergence threshold. When energy_cov, grad_cov, and dr_cov are all met, the MECP will be set to be converged.

dr_cov

Value	A real number
Default	1.E-3

The displacement convergence threshold. When energy_cov, grad_cov, and dr_cov are all met, the MECP will be set to be converged.

orb1

This defines the electronic configuration of state 1. The format is:

orb num_electrons spin_multiplicity  alpha_MO_indices : beta_MO_indices

There can be arbitrary number of orb1, but all orbitals must be included once and only once. They are the same as orb in scfguess. See :doc:scfguess.

orb2

This defines the electronic configuration of state 2. The format is:

orb num_electrons spin_multiplicity  alpha_MO_indices : beta_MO_indices

There can be arbitrary number of orb2, but all orbitals must be included once and only once. They are the same as orb in scfguess. See :doc:scfguess.

frag1

This defines the fragmentation of state 1. The format is:

frag num_electrons spin_multiplicity atom_range

There can be arbitrary number of frag1, but all atoms must be included once and only once. They are the same as frag in scfguess. See :doc:scfguess.

frag2

This defines the fragmentation of state 1. The format is:

frag num_electrons spin_multiplicity atom_range

There can be arbitrary number of frag2, but all atoms must be included once and only once. They are the same as frag in scfguess. See :doc:scfguess.

Hint

When frag1/2 and orb1/2 are defined simultaneously, orb1/2 will be considered in priority.