// Parses MCF wavefunction.
internal static SparseMultiCFWavefunction <SpinOrbital> ToSparseMultiCFWavefunction(List <List <string> > superposition)
{
var outputState = new SparseMultiCFWavefunction <SpinOrbital>();
// Todo: modify broombridge to have explicit reference state.
foreach (var element in superposition)
{
// First item is the amplitude.
double amplitude = double.Parse(element.First().ToString(), System.Globalization.CultureInfo.InvariantCulture);
// Second to Second-last are fermion operators.
IEnumerable <LadderOperator <SpinOrbital> > operators = element
.Take(element.Count() - 1)
.Skip(1)
.Select(o => V0_1.ParsePolishNotation(o.ToString()));
var ladderSequence = new LadderSequence <SpinOrbital>(operators);
// Sort operators to index order.
IEnumerable <IndexOrderedSequence <SpinOrbital> > sortedOperators = ladderSequence.ToIndexOrder();
// Only select the shortest term with no repeated indices.
IndexOrderedSequence <SpinOrbital> sortedOperator = sortedOperators.ToList().OrderBy(o => o.UniqueIndices()).First();
outputState.Set(sortedOperator, new Complex(amplitude, 0.0));
}
return(outputState);
}
public void Empty()
{
var term = new LadderSequence(new List <LadderOperator>());
var term2 = new LadderSequence(new List <LadderOperator>());
Dictionary <LadderSequence, double> dictionary = new Dictionary <LadderSequence, double>();
dictionary.Add(term, 0.5);
Assert.Equal(0.5, dictionary[term2]);
}
public void NotPassByReference()
{
var ints = new[] { 1, 2, 4, 3 };
var op = new[] { 1, 2, 4, 3 }.ToLadderSequence();
var newTerm = new LadderSequence(op);
ints[2] = 5;
Assert.Equal(op.Sequence, newTerm.Sequence);
op.Sequence[2] = new LadderOperator(RaisingLowering.d, 6);
Assert.NotEqual(op.Sequence, newTerm.Sequence);
var newTerm2 = new LadderSequence(ints.ToLadderSequence());
ints[1] = 0;
Assert.Equal(2, newTerm2.Sequence[1].Index);
var op2 = new[] { (u, 2), (d, 5), (d, 8) };
// Parses UCC wavefunction.
internal static UnitaryCCWavefunction <SpinOrbital> ToUnitaryCCWavefunction(ClusterOperator clusterOperator)
{
var outputState = new UnitaryCCWavefunction <SpinOrbital>();
var oneBodyTerms = clusterOperator.OneBodyAmplitudes ??
new List <List <string> >();
var twoBodyTerms = clusterOperator.TwoBodyAmplitudes ??
new List <List <string> >();
foreach (var element in oneBodyTerms.Concat(twoBodyTerms))
{
// First item is the amplitude.
double amplitude = double.Parse(element.First().ToString(), System.Globalization.CultureInfo.InvariantCulture);
// Second to last are fermion operators.
IEnumerable <LadderOperator <SpinOrbital> > operators = element
.Skip(1)
.Select(o => V0_1.ParsePolishNotation(o.ToString()));
var ladderSequence = new LadderSequence <SpinOrbital>(operators);
// Terms are assumed to be in normal order.
var sortedOperator = new IndexOrderedSequence <SpinOrbital>(operators);
outputState.Set(sortedOperator, new Complex(amplitude, 0.0));
}
var reference = new List <List <string> >()
{
clusterOperator.Reference
};
outputState.Reference = new SingleCFWavefunction <SpinOrbital>(
ToSparseMultiCFWavefunction(reference).Excitations.Single().Key.ToIndices()
);
return(outputState);
}
/// <summary>
/// Construct fermion term instance from a normal-ordered sequence of ladder operators.
/// </summary>
/// <param name="ladderOperators">Normal-ordered sequence of ladder operators.</param>
public FermionTerm(LadderSequence <int> ladderOperators) : base(ladderOperators)
{
}
/// <summary>
/// Constructs a Hermitian fermion term from a normal-ordered sequence of ladder operators.
/// </summary>
/// <param name="ladderOperators">Normal-ordered sequence of ladder operators.</param>
public HermitianFermionTerm(LadderSequence <int> ladderOperators) : base(ladderOperators)
{
NormalizeToCanonicalOrder();
}
