Indexing error in for computing Casida matrix
The Casida matrix is Hermitian, thus only one half and the diagonal have to be computed. In the indexing for even matrix sizes, however, there is a bug, computing some elements twice while leaving others at zero.
This error was introduced when changing the parallelization scheme for computing the Casida matrix in casida_get_matrix in commit be4e74b7.
A fix is available in commit f9e5bf0c.
If this is considered urgent enough, I can create a hotfix branch for master.