sPuReMD: add support for using the Tensorflow machine learning library to prediction initial guesses for the charge solver using the long short-term memory model (LSTM) via frozen models in GraphDef files.

sPuReMD: fix deadlock condition in BiCGStab (global shared variables in Norm and Dot functions could overwritten in some multi-threaded runs). Remove debugging prints.

sPuReMD: fix small formatting issue with writing out PDB formatted files. Fix issue with bond restrictions when running with BGF formatted geometry files. Respect buffer size of snprintf calls.

sPuReMD: small updates to Python wrapper (data structure changes). Fix issue with system energies not being computed for step 0 with the wrapper.

sPuReMD: fix issue with far neighbor list being incorrectly generated on MD steps where the list was not being computed (issue with atomic distances being incorrectly computed for peroidic neighbors). Disable several debugging print statements (DEBUG -> DEBUG_FOCUS). Other code clean-up.

PuReMD: code refactoring to remove global variables (similar to sPuReMD). sPuReMD: minor refactoring to match naming conventions of PuReMD.

sPuReMD: fix issue with SMALL_BOX_SUPPORT incorrectly computing pairwise atomic distances for periodic self-images. Fix issue with integer vector sum function (used in bond order and torsion interactions).

sPuReMD: remove global variable (array of function pointers for printing bonded interactions during debugging).

PuReMD: clean-up of heuristic for dynamically determining when to recompute the preconditioner for the charge solver.

sPuReMD: improvements for building in debug mode (add assertion support for run-time checks). Fix issue with Verlet list recomputation logic being incorrect. Fixes to be string comparisons.

sPuReMD: fix issue with certain preconditioners not being initialized for runs using restart files. Fix issue with part of simulation box struct not being initialized for runs using restart files (box->min). Other code clean-up from debugging issues with SMALL_BOX_SUPPORT.

sPuReMD: add safety check for BGF input files (CRYSTX). Remove compiler warnings when enabling DEBUG_FOCUS.

sPuReMD: fix issues with using sizeof with dynamically allocated pointers. Change OpenMP schedule policies for linear algebra code. PuReMD: correct discrepancy with charge matrix construction. Enable dual solver for charges by default.

sPuReMD: refactoring to better align with PuReMD code. PuReMD: backport sPuReMD changes from validation efforts against Fortran ReaxFF code.

sPuReMD: fixes to SAI preconditioner to correctly apply threshold to negative entries and to handle EE/ACKS2 cases when a threshold value of 1.0 is chosen.

sPuReMD: fix bug with diagonal scaling during FG_ICHOL/FG_ILUT producing incorrect factorizations when diagonal entries were negative.

sPuReMD: complete fine-grained Cholesky implementation. TODO: fix numeric breakdowns with water 6540 atom system.

sPuReMD: workarounds for memory issues with ILUT factors. Implement ILU(0) and call when selecting ILUT with a droptol of 0.