Dimer ASD¶
Description¶
The active space decomposition algorithm for molecular dimers allows for efficient computation of the dimer’s complete-active-space wave functions. The current algorithm works for dimer molecules whose fragments are not covalently linked. Full-CI and restricted-active-space-CI can be used to obtain the fragment state wave functions. ASD calculation starts with dimer molecule construction, see Dimer Construction section for more information.
Dimer Construction¶
Keywords¶
Required Keywords¶
method
Description: Method to compute active subspaces.
Datatype: string
Value:
cas
or fci
: use full configuration interaction methodras
: use restricted active space configuration interaction methodfci
Description: If
fci
is used, specify the implementations here.Recommendation: See Full configuration interaction (FCI) for details.
ras
Description: If
ras
is used, specify the implementations here.Recommendation: See Restricted active space configuration interaction (RASCI) for details.
space
Description: Specify important fragment states with the following keys:
charge
, spin
, nstate
Recommendation: See sample input for details.
Optional Keywords¶
nstates
Description: Number of target states.
Datatype: int
Default 10
charge
Description: Dimer charge.
Datatype: int
Default: 0
nspin
Description: Number of dimer total spin.
Datatype: int
Default: 0
nguess
Description: Number of initial guess state vectors for Davidson diagonalization.
Datatype: int
Default: \(10\times nstates\)
Davidson_subspace
Description: Size of Davidson subspace.
Datatype: int
Default: 10
max_iter
Description: Maximum number of iterations for Davidson diagonalization.
Datatype: int
Default: 50
dipoles
Description: Whether to calculate dipole moment.
Datatype: bool
Default: false
thresh
Description: Threshold for convergence in Davidson diagonalization.
Datatype: double
Default: \(1.0\times 10^{-7}\)
print_thresh
Description: Threshold for printing out important configurations.
Datatype: double
Default: 0.01
store matrix
Description: Whether the Hamiltonian matrix is stored.
Datatye: bool
Default: false
print_info
Description: Whether print out information (e.g. reduced density matrix and energy).
Datatype: bool
Default: false
Example¶
Here is a sample calculation of a benzene dimer molecule.
Sample input¶
{ "bagel" : [
{
"title" : "molecule",
"basis" : "svp",
"df_basis" : "svp-jkfit",
"angstrom" : false,
"cartesian" : false,
"geometry" : [
{"atom" :"C", "xyz" : [ 0.00000000000, 0.00000000000, 2.64112304663] },
{"atom" :"C", "xyz" : [ 2.28770766388, 0.00000000000, 1.32067631141] },
{"atom" :"C", "xyz" : [ 2.28770047235, 0.00000000000, -1.32071294538] },
{"atom" :"C", "xyz" : [ 0.00000000000, 0.00000000000, -2.64114665444] },
{"atom" :"C", "xyz" : [ -2.28770047235, 0.00000000000, -1.32071294538] },
{"atom" :"C", "xyz" : [ -2.28770766388, 0.00000000000, 1.32067631141] },
{"atom" :"H", "xyz" : [ 4.07221260176, 0.00000000000, 2.35164689765] },
{"atom" :"H", "xyz" : [ 4.07221517814, 0.00000000000, -2.35163163881] },
{"atom" :"H", "xyz" : [ 0.00000000000, 0.00000000000, -4.70191324441] },
{"atom" :"H", "xyz" : [ -4.07221517814, 0.00000000000, -2.35163163881] },
{"atom" :"H", "xyz" : [ -4.07221260176, 0.00000000000, 2.35164689765] },
{"atom" :"H", "xyz" : [ 0.00000000000, 0.00000000000, 4.70197960246] }
]
},
{
"title" : "hf"
},
{
"title" : "dimerize",
"angstrom" : true,
"translate" : [0.0, 4.0, 0.0],
"dimer_active" : [17, 20, 21, 22, 23, 24],
"hf" : {
"thresh" : 1.0e-12
},
"localization" : {
"max_iter" : 50,
"thresh" : 1.0e-8
}
},
{
"title" : "asd",
"method" : "cas",
"store_matrix" : false,
"space" : [
{ "charge" : 0, "spin" : 0, "nstate" : 3},
{ "charge" : 0, "spin" : 2, "nstate" : 3},
{ "charge" : 1, "spin" : 1, "nstate" : 3},
{ "charge" :-1, "spin" : 1, "nstate" : 3}
],
"fci" : {
"thresh" : 1.0e-6,
"algorithm" : "kh",
"nguess" : 400
},
"nstates" : 5
}
]}
Reference¶
Description of Reference | Reference |
---|---|
Active Space Decompotion Method | S. M. Parker, T. Seideman, M. A. Ratner, and T. Shiozaki, J. Chem. Phys. 139, 021108 (2013). |