> internal coordinates SHOULD be very easy to use, particularly if they are > handed > to you and you don't have to generate them yourself. They are amazingly > concise.
We are already handling fractional coordinates, so adding another coordinate system will not be difficult ... IF ... > The only complication I can imagine is that they sometimes involve > "phantom" or > "temporary" atoms for starting points. > > For example, in this example we have a first atom at 0,0,0, then two > phantom > atoms on roughly perpendicular axes. They define the starting point for > the next > dihedral, and you are off and running. Mostly QM programs start with these > so as > to define positions when symmetry is an issue. > > ATOM CHEMICAL BOND LENGTH BOND ANGLE TWIST ANGLE > NUMBER SYMBOL (ANGSTROMS) (DEGREES) (DEGREES) > (I) NA:I NB:NA:I NC:NB:NA:I NA > NB > NC > 1 C( 1) 0.000000 0.000000 0.000000 > > 2 XX( ) 4.117293 0.000000 0.000000 1 > > 3 XX( ) 2.303156 90.000000 0.000000 2 > 1 > > 4 C( 2) 1.351924 * 133.488008 * 180.000000 * 1 > 2 ... IF ... there are three floats per atom. Q: Is it the case that there are only 3 numbers per atom? bondLength, BondAngle, and TorsonAngle? Q: What are NA, NB, and NC? Miguel ------------------------------------------------------- This SF.Net email is sponsored by: Oracle 10g Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE. http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click _______________________________________________ Jmol-developers mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jmol-developers
