NaN in short-LiH_ae-vmc_msdj-1-16

[prckent]

Describe the bug

NaN guard tripped with grads[1]=-nan for particle 2 in gcc no mpi mixed debug build.

https://cdash.qmcpack.org/testSummary.php?project=1&name=short-LiH_ae-vmc_msdj-1-16&date=2024-09-23

All the other builds are behaving, so hopefully more of a precision issue than a logic bug. From the pass/fail log, occurs about 1 in 10 runs.

To Reproduce

develop, ctest -R short-LiH_ae-vmc_msdj-1-16

Expected behavior

No NaN.

System:

nitrogen2