public Dictionary <FermionTermType, Double> ComputeOneNorms()
{
return(FermionTerms.ToDictionary(
(termTypePair) => termTypePair
.Key,
(termTypePair) => termTypePair
.Value
.AsParallel()
.Select(o => Abs(o.coeff))
.Sum()
));
}
/// <summary>
/// This approximates the Hamiltonian ground state by a greedy algorithm
/// that minimizes only the PP term energies. If there are no PP terms,
/// states will be occupied in lexicographic order.
/// </summary>
/// <returns>
/// Greedy trial state for minimizing Hamiltonian diagonal one-electron energy.
/// </returns>
public InputState GreedyStatePreparation()
{
var label = "Greedy";
(Double, Double)coeff = (1.0, 0.0);
var conjugate = Enumerable.Range(0, (int)NElectrons).Select(o => (Int64)1).ToArray();
if (FermionTerms.ContainsKey(PPTermType))
{
var hPPTermSortedByCoeff = FermionTerms[PPTermType];
var spinOrbitals = hPPTermSortedByCoeff.OrderBy(o => o.coeff).Select(o => o.SpinOrbitalIndices.First()).Take((int)NElectrons).ToArray();
var fermionTerm = new FermionTerm(conjugate, spinOrbitals, 1.0);
fermionTerm.ToSpinOrbitalCanonicalOrder();
fermionTerm.coeff = 1.0;
var superposition = new((Double, Double), FermionTerm)[] {
