forte2.state.state

Module Contents

class forte2.state.state.State

Class to represent a state of a quantum system.

Parameters:

multiplicityint, required for non-relativisitic states.

Multiplicity of the state (2S+1).

msfloat, required for non-relativisitic states.

Spin projection (Ms) of the state.

nelint, optional

Total number of electrons in the state. If not provided, it is calculated from the system and charge.

systemSystem, optional

The system to which this state belongs. If not provided, nel must be specified.

chargeint, optional, default=0

Charge of the state. Used to calculate the number of electrons if system is provided. Ignored if nel is provided.

irrepint, optional

Irreducible representation of the state in Cotton ordering.

gas_minlist[int], optional, default=[]

Minimum number of electrons in each GAS. If not provided, no occupation restrictions will be applied. If the length of gas_min is smaller than the number of GASes, the restrictions will be sequentially applied to GAS1, GAS2, until the end of gas_min, beyond which no restrictions will be applied.

gas_maxlist[int], optional, default=[]

Maximum number of electrons in each GAS. Processed similarly to gas_min.

symmetry: int, optional, default=0

Symmetry of the state.

symmetry_label: str, optional, default=None

Label for the symmetry of the state.

multiplicity: int

ms: float

nel: int = None

system: forte2.system.System = None

charge: int = 0

gas_min: list[int] = []

gas_max: list[int] = []

symmetry: int = 0

symmetry_label: str = None

na: int

nb: int

twice_ms: int

multiplicity_label() → str

Return the label for the multiplicity of the state.

str_minimum() → str

Return a minimal string representation of the state.

str_short() → str

Return a short string representation of the state.

static get_ms_string(twice_ms: int) → str

Return a string representation of Ms based on its value.

class forte2.state.state.RelState

Bases: State

A convenience class representing a relativistic electronic state. Multiplicity and ms are no longer required, but will be used for initial guesses if provided.

multiplicity: int = None

ms: float = None

class forte2.state.state.StateAverageInfo

A class to hold information about state averaging in multireference calculations.

Parameters:

stateslist[State] | State

A list of State objects or a single State object representing the electronic states. This also includes the gas_min and gas_max attributes.

nrootslist[int] | int, optional, default=1

A list of integers specifying the number of roots for each state. If only one state is provided, this can be a single integer.

weightslist[list[float]], optional

A list of lists of floats specifying the weights for each root in each state. These do not have to be normalized, but must be non-negative. If not provided, equal weights are assigned to each root.

Attributes:

ncisint

The number of CI states, which is the length of the states list.

nroots_sumint

The total number of roots across all states.

weights_flatNDArray

A flattened array of weights for all roots across all states.

states: list[State] | State

nroots: list[int] | int = 1

weights: list[list[float]] = None

pretty_print_sa_info()

Pretty print the state averaging information.