The error was located in diagram D8a from Shavitt & Bartlett. Shavitt & Bartlett give the opposite sign for this contraction as opposed to Gauss & Stanton and SymPy. We chose to go with the sign used in the expression from the latter two. This fixes #2.
The error was located in diagram D8a from Shavitt & Bartlett. Shavitt & Bartlett give the opposite sign for this contraction as opposed to Gauss & Stanton and SymPy. We chose to go with the sign used in the expression from the latter two. This fixes #2.