CCL:G: ADMP total kinetic energy related to velocities

 Sent to CCL by: "Dario Gregorio Perez" [derwiszck|-|gmail.com]
 Hello all CCL Subscribers,
 I would like to focus on a problem that I obtained with ADMP (Atom Centered
 Density Matrix Propagation) implemented in gaussian.
 I am trying to calculate the kinetic energies from velocities.
 As you know we can define the NKE (nuclear kinetic energy) in the input and
 program randomly generate us the velocities. However, generated velocities:
  ADMP step      0
  GnVelC Random: Velocity
  I=    1 X=   3.398782212293D-01 Y=   1.465871681630D-01 Z=   6.424346183195D-01
  I=    2 X=   5.013104147695D-01 Y=   3.472184481623D-01 Z=   5.311228776839D-01
  I=    3 X=   8.478196138519D-01 Y=   4.055930070705D-01 Z=   6.444282418968D-01
  I=    4 X=   1.676431686815D-01 Y=   2.277398149910D-01 Z=   6.024104048879D-02
  I=    5 X=   1.732845504177D-01 Y=   9.368130619597D-01 Z=   5.517780556128D-01
  I=    6 X=   6.893582811025D-01 Y=   4.348692854433D-01 Z=   3.349183234847D-02
  I=    7 X=   7.669745262782D-01 Y=   4.634406180743D-01 Z=   8.149850049870D-01
  I=    8 X=   5.653485273988D-01 Y=   6.683079621588D-01 Z=   1.607799839639D-01
  I=    9 X=   6.846587566952D-01 Y=   6.774363692626D-01 Z=   9.833239520217D-01
  I=   10 X=   6.558141826505D-01 Y=   2.262089648952D-01 Z=   9.651211563677D-01
  I=   11 X=   8.738928624306D-01 Y=   9.862285094204D-01 Z=   9.754484548179D-01
  I=   12 X=   5.057309487267D-01 Y=   7.118213486021D-01 Z=   8.452797536316D-01
  I=   13 X=   7.157120462557D-01 Y=   8.235984112087D-01 Z=   7.521027257725D-02
  GnVelC Scaled: Velocity
  I=    1 X=   4.697014674563D-02 Y=   2.025790524247D-02 Z=   8.878252977727D-02
  I=    2 X=   6.927958979445D-02 Y=   4.798454400516D-02 Z=   7.339958239907D-02
  I=    3 X=   1.171661177124D-01 Y=   5.605173227103D-02 Z=   8.905804255253D-02
  I=    4 X=   2.316778111110D-02 Y=   3.147295667036D-02 Z=   8.325130400041D-03
  I=    5 X=   2.394740307993D-02 Y=   1.294647442673D-01 Z=   7.625406579277D-02
  I=    6 X=   9.526723867914D-02 Y=   6.009762578655D-02 Z=   4.628470381238D-03
  I=    7 X=   1.059935700474D-01 Y=   6.404609792326D-02 Z=   1.126284736376D-01
  I=    8 X=   7.812946413071D-02 Y=   9.235814798704D-02 Z=   2.221930964929D-02
  I=    9 X=   9.461777855709D-02 Y=   9.361966636168D-02 Z=   1.358924092220D-01
  I=   10 X=   9.063154527979D-02 Y=   3.126139779676D-02 Z=   1.333768376742D-01
  I=   11 X=   1.207693621552D-01 Y=   1.362938103084D-01 Z=   1.348040392229D-01
  I=   12 X=   6.989049427639D-02 Y=   9.837156696767D-02 Z=   1.168151166779D-01
  I=   13 X=   9.890924966787D-02 Y=   1.138188204411D-01 Z=   1.039383319989D-02
  GnVelC MW: Velocity
  I=    1 X=  -7.767235652917D-03 Y=  -8.629435985058D-02 Z=  -2.943473782054D-02
  I=    2 X=  -1.051105078791D-03 Y=  -3.895073834557D-02 Z=  -2.234634745708D-02
  I=    3 X=   3.993532120872D-02 Y=  -6.509787237278D-03 Z=   3.797451060452D-02
  I=    4 X=  -7.340768346256D-02 Y=  -2.927558997435D-02 Z=  -3.158980977140D-02
  I=    5 X=  -9.115183242473D-02 Y=   4.121349582598D-02 Z=  -4.331312607715D-02
  I=    6 X=   6.204152852713D-03 Y=  -7.243917416043D-04 Z=  -3.186792874862D-02
  I=    7 X=   8.686570687864D-02 Y=   3.810551973465D-02 Z=   8.400773139458D-02
  I=    8 X=   6.267344029835D-02 Y=   5.941458318215D-02 Z=  -1.843245336307D-02
  I=    9 X=   8.105817639074D-02 Y=   6.647616584633D-02 Z=   1.075468825745D-01
  I=   10 X=   5.858619789816D-02 Y=   6.284739985947D-04 Z=   8.940120953276D-02
  I=   11 X=   8.018795918517D-02 Y=   1.128080348882D-01 Z=   1.008359087201D-01
  I=   12 X=   3.293437281697D-02 Y=   7.532804416915D-02 Z=   8.543617786663D-02
  I=   13 X=   7.472863614520D-02 Y=   1.030715738732D-01 Z=   9.256829738788D-03
  GnVelC Scaled: Velocity
  I=    1 X=  -1.083126389307D-02 Y=  -1.203358602458D-01 Z=  -4.104618775637D-02
  I=    2 X=  -1.465746244412D-03 Y=  -5.431607134159D-02 Z=  -3.116156083960D-02
  I=    3 X=   5.568905360863D-02 Y=  -9.077775750015D-03 Z=   5.295474013503D-02
  I=    4 X=  -1.023656326255D-01 Y=  -4.082425908095D-02 Z=  -4.405139502076D-02
  I=    5 X=  -1.271095143043D-01 Y=   5.747144404967D-02 Z=  -6.039933890757D-02
  I=    6 X=   8.651574354571D-03 Y=  -1.010150646367D-03 Z=  -4.443922669866D-02
  I=    7 X=   1.211325929203D-01 Y=   5.313742990063D-02 Z=   1.171471999116D-01
  I=    8 X=   8.739693261438D-02 Y=   8.285251771665D-02 Z=  -2.570370920794D-02
  I=    9 X=   1.130341009867D-01 Y=   9.269976180145D-02 Z=   1.499721030871D-01
  I=   10 X=   8.169735003318D-02 Y=   8.763951594743D-04 Z=   1.246683036384D-01
  I=   11 X=   1.118205994761D-01 Y=   1.573086809428D-01 Z=   1.406137763870D-01
  I=   12 X=   4.592636287524D-02 Y=   1.050435394784D-01 Z=   1.191391416251D-01
  I=   13 X=   1.042076762733D-01 Y=   1.437313693547D-01 Z=   1.290847480292D-02
  do not match to nuclear kinetic energy  given in the input. Moreover, they are
 few times bigger (around 3.5 times than given energy). I tried to calculate KE
 including for both: "pure" and scaled. Without success.
 Due to that problem I would like to ask you:
 1. Total kinetic energy is: translation kinetic energy + rotation KE and
 vibration KE. Gaussian output print in the ADMP step 0 this:
 Summary information for step      0
  Time (fs)     0.000000
  EKinC      =      0.1567570; EKinPA =      0.0000000; EKinPB =      0.0000000
  EKin       =      0.1567570; EPot   =   -322.7887432; ETot   =   -322.6319862
  ETot-EKinP =   -322.6319862
  Integrand for the Velocity-Velocity Auto-Correlation  Function =
 2.939453785855D-01
  Angular momentum
    JX = -0.2072213981D-13  JY = -0.5055706342D-14  JZ =  0.1946845813D-13
  Jtot =  0.2887885224D-13 H-BAR;  J (Quantum Number) =  0.0000000000D+00
  Total energy  -3.226319862D+02 A.U.
  Total angular momentum   2.887885D-14 h-bar
 So, EKinC is the total kinetic energy. So keyword NKE in referring to total
 kinetic energy. Does it mean that include also not only vibrational part but
 also translational and rotational.
 Rotational looks negligible  (Jtot =  0.2887885224D-13 H-BAR) so does it mean
 that velocities "contain" translational and vibrational part?
 Later to do dynamic velocities are scaled again by factor of 10^15. Why?
 Is it just to minimized the numerical errors?
 Summary.
 Total kinetic energy calculated as:
 KE=SUM[i=1 to N](0.5*m"i"*|V"i"|) gives me value
 0.5563189665 in a.u.
 Which is much bigger than printed in gaussian.
 Than I remove translational part considering that TKE is momentum^2/2m so,
 TKE=1/2M SUM[i=1 to N] (m"i"^2*v"i"^2), where M is total
 mass.
 TKE=0.0691092388
 Than when I substract (KE-TKE) I should get vibrational KE, which is still much
 bigger that the one printed by gaussian.
 Please, can you drive me through this problem, where is the error?
 Units follow by ADMP maunal should be in a.u (??bohr/sec??).
 Thank you,
 Darek