nwchem 6.3 NEB calculation with midpoint


Gets Around
I ran NEB task with midpoint defined
title "cubane nudged elastic band TS search SVP with CASSCF(2,2)"
 
scratch_dir /mnt/scratch
 
geometry noautosym noautoz nocenter
 H      -1.407657     -1.407657     -1.407657
 C      -0.779454     -0.779454     -0.779454
 H      -1.407657     -1.407657      1.407657
 C      -0.779454     -0.779454      0.779454
 H      -1.407657      1.407657     -1.407657
 C      -0.779454      0.779454     -0.779454
 H       1.407657     -1.407657     -1.407657
 C       0.779454     -0.779454     -0.779454
 H      -1.407657      1.407657      1.407657
 C      -0.779454      0.779454      0.779454
 H       1.407657     -1.407657      1.407657
 C       0.779454     -0.779454      0.779454
 H       1.407657      1.407657     -1.407657
 C       0.779454      0.779454     -0.779454
 H       1.407657      1.407657      1.407657
 C       0.779454      0.779454      0.779454
end
 
geometry midgeom noautosym noautoz nocenter
 H      -1.378491     -1.376439     -1.673141
 C      -0.620604     -0.619967     -1.490818
 H      -1.181144     -1.179502      2.158209
 C      -0.725374     -0.724645      1.292256
 H      -1.383769      1.505731     -1.308703
 C      -0.761552      0.731364     -0.863090
 H       1.503543     -1.387461     -1.308712
 C       0.730455     -0.763594     -0.863187
 H      -1.480745      1.409811      1.212953
 C      -0.830565      0.667849      0.754035
 H       1.407537     -1.484345      1.212725
 C       0.666865     -0.832551      0.754016
 H       1.424352      1.421080     -1.383200
 C       0.792917      0.790738     -0.761648
 H       1.300556      1.297404      1.499159
 C       0.729639      0.727523      0.769183
end

geometry endgeom noautosym noautoz nocenter
 H      -1.404845     -1.397517     -1.854825
 C      -0.664811     -0.683844     -1.513223
 H      -1.404844     -1.397517      1.854823
 C      -0.664810     -0.683844      1.513221
 H      -1.346664      1.443074     -1.250923
 C      -0.776144      0.638288     -0.788395
 H       1.404844     -1.397518     -1.854825
 C       0.664810     -0.683845     -1.513223
 H      -1.346664      1.443073      1.250924
 C      -0.776144      0.638287      0.788395
 H       1.404845     -1.397515      1.854826
 C       0.664810     -0.683843      1.513222
 H       1.346664      1.443074     -1.250923
 C       0.776144      0.638287     -0.788395
 H       1.346664      1.443073      1.250924
 C       0.776144      0.638287      0.788395
end

basis
 H library def2-SVP
 C library def2-SVP
end

mcscf
 active 2
 actelec 2
 multiplicity 1
 vectors atomic
 maxiter 1000
end

neb
 nbeads 5
 maxiter 10
 hasmiddle
end

task mcscf neb


After sucessfull computation first bead. I've got error with second.
 !! The overlap matrix has  12 vectors deemed linearly dependent with
    eigenvalues:
 7.28D-10 2.54D-08 2.79D-08 5.90D-08 3.11D-07 5.42D-07 8.67D-07 1.32D-06
 1.76D-06 2.81D-06 4.23D-06 5.91D-06

 ------------------------------------------------------------------------
 mcscf:linear dependent AO basis        0
 ------------------------------------------------------------------------
 There is an error in the specified basis set


I think second bead geometry is wrong because when I run this task without midgeomery and set endgeom to midgeom all works fine.
How I can get all beads geometryes between startgeometry and midgeometry to verify my sugestion.

Gets Around
I run other task with all three geometries are equal and I've found that bead_2 geometry is wrong.
All coordinates in Bohr radius units.
                         RHF ENERGY GRADIENTS
  
    atom               coordinates                        gradient
                 x          y          z           x          y          z
   1 H      -1.496298  -1.496298  -1.496298    0.891779   0.891779   0.891779
   2 C      -0.828537  -0.828537  -0.828537    1.684386   1.684386   1.684386
   3 H      -1.496298  -1.496298   1.496298    0.891779   0.891779  -0.891779
   4 C      -0.828537  -0.828537   0.828537    1.684386   1.684386  -1.684386
   5 H      -1.496298   1.496298  -1.496298    0.891779  -0.891779   0.891779
   6 C      -0.828537   0.828537  -0.828537    1.684386  -1.684386   1.684386
   7 H       1.496298  -1.496298  -1.496298   -0.891779   0.891779   0.891779
   8 C       0.828537  -0.828537  -0.828537   -1.684386   1.684386   1.684386
   9 H      -1.496298   1.496298   1.496298    0.891779  -0.891779  -0.891779
  10 C      -0.828537   0.828537   0.828537    1.684386  -1.684386  -1.684386
  11 H       1.496298  -1.496298   1.496298   -0.891779   0.891779  -0.891779
  12 C       0.828537  -0.828537   0.828537   -1.684386   1.684386  -1.684386
  13 H       1.496298   1.496298  -1.496298   -0.891779  -0.891779   0.891779
  14 C       0.828537   0.828537  -0.828537   -1.684386  -1.684386   1.684386
  15 H       1.496298   1.496298   1.496298   -0.891779  -0.891779  -0.891779
  16 C       0.828537   0.828537   0.828537   -1.684386  -1.684386  -1.684386


Input file is
title "cubane nudged elastic band TS search SVP"

geometry noautosym noautoz nocenter
 H      -1.407657     -1.407657     -1.407657
 C      -0.779454     -0.779454     -0.779454
 H      -1.407657     -1.407657      1.407657
 C      -0.779454     -0.779454      0.779454
 H      -1.407657      1.407657     -1.407657
 C      -0.779454      0.779454     -0.779454
 H       1.407657     -1.407657     -1.407657
 C       0.779454     -0.779454     -0.779454
 H      -1.407657      1.407657      1.407657
 C      -0.779454      0.779454      0.779454
 H       1.407657     -1.407657      1.407657
 C       0.779454     -0.779454      0.779454
 H       1.407657      1.407657     -1.407657
 C       0.779454      0.779454     -0.779454
 H       1.407657      1.407657      1.407657
 C       0.779454      0.779454      0.779454
end

geometry midgeom noautosym noautoz nocenter
 H      -1.407657     -1.407657     -1.407657
 C      -0.779454     -0.779454     -0.779454
 H      -1.407657     -1.407657      1.407657
 C      -0.779454     -0.779454      0.779454
 H      -1.407657      1.407657     -1.407657
 C      -0.779454      0.779454     -0.779454
 H       1.407657     -1.407657     -1.407657
 C       0.779454     -0.779454     -0.779454
 H      -1.407657      1.407657      1.407657
 C      -0.779454      0.779454      0.779454
 H       1.407657     -1.407657      1.407657
 C       0.779454     -0.779454      0.779454
 H       1.407657      1.407657     -1.407657
 C       0.779454      0.779454     -0.779454
 H       1.407657      1.407657      1.407657
 C       0.779454      0.779454      0.779454
end

geometry endgeom noautosym noautoz nocenter
 H      -1.407657     -1.407657     -1.407657
 C      -0.779454     -0.779454     -0.779454
 H      -1.407657     -1.407657      1.407657
 C      -0.779454     -0.779454      0.779454
 H      -1.407657      1.407657     -1.407657
 C      -0.779454      0.779454     -0.779454
 H       1.407657     -1.407657     -1.407657
 C       0.779454     -0.779454     -0.779454
 H      -1.407657      1.407657      1.407657
 C      -0.779454      0.779454      0.779454
 H       1.407657     -1.407657      1.407657
 C       0.779454     -0.779454      0.779454
 H       1.407657      1.407657     -1.407657
 C       0.779454      0.779454     -0.779454
 H       1.407657      1.407657      1.407657
 C       0.779454      0.779454      0.779454
end
basis
 H library def2-SVP
 C library def2-SVP
end
 
neb
 nbeads 9
 maxiter 10
 hasmiddle
end
 
task scf neb

Gets Around
By the way.
In http://nwchemgit.github.io/index.php/Release62:Nudged_Elastic_Band_%28NEB%29_and_Zero_Temper...
second formula [[1]] for Linear interpolation between three geometries is wrong.

When i = nbeads, R[i] <> last geometry.


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