PDB FILE WRITER

Fortran:

	! module, output a single frame (pdb "model") of the trajectory. This has
	! nothing to do with OpenMM.
	SUBROUTINE myWritePDBFrame(frameNum, timeInPs, energyInKcal)
	use MyAtomInfo; implicit none
	integer frameNum; real*8 timeInPs, energyInKcal
	integer n
	print "('MODEL',5X,I0)", frameNum
	print "('REMARK 250 time=', F0.3, ' picoseconds; Energy=', F0.3, ' kcal/mole')", &
	timeInPs, energyInKcal
	do n = 1,NumAtoms
	print "('ATOM ', I5, ' ', A4, ' SLT 1 ', 3F8.3, ' 1.00 0.00')", &
	n, atoms(n)%pdb, atoms(n)%posInAng
	end do
	print "('ENDMDL')"
	END SUBROUTINE

C++:

	static void
	myWritePDBFrame(int frameNum, double timeInPs, double energyInKcal,
	const MyAtomInfo atoms[])
	{
	// Write out in PDB format -- printf is so much more compact than formatted cout.
	printf("MODEL %d\n", frameNum);
	printf("REMARK 250 time=%.3f ps; energy=%.3f kcal/mole\n",
	timeInPs, energyInKcal);
	for (int n=0; *atoms[n].pdb; ++n)
	printf("ATOM %5d %4s SLT 1 %8.3f%8.3f%8.3f 1.00 0.00\n",
	n+1, atoms[n].pdb,
	atoms[n].posInAng[0], atoms[n].posInAng[1], atoms[n].posInAng[2]);
	printf("ENDMDL\n");
	}

參考
https://github.com/pandegroup/openmm/blob/master/examples/HelloSodiumChlorideInFortran.f90
https://github.com/pandegroup/openmm/blob/master/examples/HelloSodiumChloride.cpp