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Alex Granovsky
gran@classic.chem.msu.su

the corrected sections of your input are:

 $ZMAT 
      SCAN=.T. 
      IFZMAT(1)=1,1,11 NONVDW(1)=1,11
 $END                 
 $SURF
      ORIG1=1.3853635
      REUSE=.T. 
      DISP1=0.05 NDISP1=41 
 $END                                  

Actually, the problem is caused by ORIG1=0 directive,
which sets bond length to zero so that torsions and
angle variables are singular.  

Note that for DLC scans, ORIG1 and ORIG2 mean absolute values,
i.e., not relative to the starting structure. This is indeed a
little bit inconsistent and will be refined in the future.

Regards,
Alex Granovsky




On Tue May 5 '09 11:36am, Talipov Marat R. wrote
------------------------------------------------
>I receive "Severe error: singular angular variable!" message when I try to scan bond lendth. Input coords are in XYZ format, internal coords are succesfully generated by DLC procedure. This case is reproduced even with EXETYP=check.

>           ** GEOMETRY CONSTRAINTS ARE BEING APPLIED. **

>          TRANSFORMING DISPLACEMENT FROM INTERNALS TO CARTESIANS
>          THE ROOT MEAN SQUARE ERROR IN ITERATION   1 IS   0.15283985
>          THE ROOT MEAN SQUARE ERROR IN ITERATION   2 IS   0.07672415
>          THE ROOT MEAN SQUARE ERROR IN ITERATION   3 IS   0.03839302
>          THE ROOT MEAN SQUARE ERROR IN ITERATION   4 IS   0.01919908
>          THE ROOT MEAN SQUARE ERROR IN ITERATION   5 IS   0.00960005
>          THE ROOT MEAN SQUARE ERROR IN ITERATION   6 IS   0.00480017
>          THE ROOT MEAN SQUARE ERROR IN ITERATION   7 IS   0.00240012
>          Severe error: singular angular variable!

>What is the source of this error?

[ This message was edited on Tue May 5 '09 at 8:59pm by the author ]