I was hoping that someone could give me some help getting started with the sympy tensor objects. I'd like to define symbolic objects to represent one- and two-electron integrals in quantum chemistry with the proper index permutation symmetries. These are real-valued integrals, so commutation relations aren't a problem (and, when they are, can be handled by the physics.secondquant module.
The one-electron integrals are symmetric, i.e. I1[i,j] = I1[j,i], which I assume should be straightforward. The two-electron integrals are a little trickier, for I2[i,j,k,l] the integral is symmetric when i,j are permuted, and/or k,l are permuted, and/or i,j is permuted with k,l. I've never been able to derive a symbolic object that captures this, and it would be really convenient, for example, to derive equations for orbital optimization for different MC-SCF wave functions. I'm familiar with techniques to compute the orbitals numerically, e.g., https://github.com/rpmuller/pyquante2. What I'm interested here is to derive and simplify equations for the symbolic manipulations of equations containing these terms. Has anyone done any work on this? Thanks in advance, Rick -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/25eff312-791d-470f-9539-2a555cb0da07%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
