Incorrect Jordan Wigner C# Encoding?

[christopherkang]

Looking for some clarification into the implementation of the Jordan Wigner transform in Q#.

QuantumLibraries/Chemistry/src/DataModel/Fermion/JordanWignerEncoding.cs

Lines 148 to 169 in 6899af4

	if (Enumerable.SequenceEqual(pqrsPermuted, prsq))
	{
	h123 = new double[] { 0.0, 0.0, coeff };
	}
	else if (Enumerable.SequenceEqual(pqrsPermuted, pqsr))
	{
	h123 = new double[] { -coeff, 0.0, 0.0 };
	}
	else if (Enumerable.SequenceEqual(pqrsPermuted, psrq))
	{
	h123 = new double[] { 0.0, -coeff, 0.0 };
	}
	else
	{
	h123 = new double[] { 0.0, 0.0, 0.0 };
	}
	v0123 = new double[] { -h123[0] - h123[1] + h123[2],
	h123[0] - h123[1] + h123[2],
	-h123[0] - h123[1] - h123[2],
	-h123[0] + h123[1] + h123[2] };

Here, we have only one of the h^(1), h^(2), h^(3) terms associated with a coefficient. When we reference the paper associated with the implementation, two should be additive inverses, while the last is 0:

(pg 13, 14 of Whitfield et al. https://arxiv.org/pdf/1001.3855.pdf)

The coefficient orderings + labelings seem to differ greatly and produce different results.

[cgranade]

@guanghaolow, do you know the status of this one? Thanks!

[guenp]

@christopherkang thank you for your bug report! We apologize for the late reply and will look into this asap.

[christopherkang]

@guenp no worries! I doubt that there's an actual issue, but greater documentation in this area would certainly be helpful (even a reference to this arxiv could be useful) Thanks!