Module initial 

Initialization procedures. Port of initial.f90, restmol.f90, cenmass.f90.

Call order matches Packmol’s initial.f90 exactly:

1. compute_dmax
2. restmol(type 0, solve=true) → sizemin/sizemax
3. first random guess (within sizemin/sizemax)
4. Phase 1: constraint-only GENCAN per type (reduced x!)
5. Rescale sizemin/sizemax + compute cm_min/cm_max per type
6. Setup cell grid + place fixed atoms
7. Random initial point using cm_min/cm_max (restmol(false) only, up to 20 tries)
8. Random angles
9. Phase 2: constraint-only GENCAN per type (reduced x!)

Structs

SwapState

Saved state for swaptype operations (mirrors swaptypemod.f90).

Functions

compute_dmax

Compute maximum internal distance per molecule type.

init_xcart_from_x

Initialize xcart from x (COM + Euler angles).

initial

Full initialization procedure. Faithful port of initial.f90.

restmol

Run a single-molecule GENCAN solve (restmol). Port of restmol.f90.