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Jan Jensen
Works at University of Copenhagen
Attended Iowa State University
Lives in Copenhagen
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Great, thank you!
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What is density functional theory? part 2 - approximations
So, DFT contains a deep truth:   Somehow just the electronic density as a function of position within a system in its lowest energy state contains, latent within it, basically all of the information about that ground state.  This is the case even though you...
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New package in Debichem: BAGEL, a quantum-chemistry package which includes relativistic corrections and has a focus on multi-reference methods. It extends the current functionality of computational chemistry packages in Debian by the following:
* Complete active space SCF (CASSCF), including analytical gradients
* Complete active space second order perturbation theory (CASPT2), including analytical gradients
* N-electron valence-state second order perturbation theory (NEVPT2)
* Mult-state internally contracted multireference configuration-interaction (ic-MRCI)

All of the above can use density-fitting as well. However, note that BAGEL does not currently have a disk interface, so computations need to fit in memory.

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The registration for the new MWM 2016 Summer School is now open.

http://cec.mpg.de/workshops/mwm2016/
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Assessment of the accuracy of coupled cluster perturbation theory for open-shell systems. I. Triples expansions
Janus J. Eriksen, Devin A. Matthews, Poul Jørgensen, and Jürgen Gauss (2015) Contributed by  Jan Jensen Figure 1: Normal distributions of the recoveries of (in percent (%), Figure 1a) and deviations from (in kcal/mol, Figure 1b) CCSDT–CCSD frozen-core/cc-p...
Figure 1: Normal distributions of the recoveries of (in percent (%), Figure 1a) and deviations from (in kcal/mol, Figure 1b) CCSDT–CCSD frozen-core/cc-pVTZ correlation energy differences for RHF, UHF, and ROHF references. (Taken from the paper). This paper argues that we shouldn't expect the ...
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Writing an impact neutral review
The idea of impact neutral reviewing was pioneered by PLoS ONE ten years ago this year. The idea is that ... PLOS ONE only verifies whether experiments and data analysis were conducted rigorously, and leaves it to the scientific community to ascertain impor...
I have now been writing impact neutral reviews for almost three years and sum up my experience so far here. 1. I review all papers with the same, impact neutral, criteria regardless of journal. I don't rank the paper in any way and if there is a required field that I don't like I just enter a ...
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What is density functional theory? part 3 - pitfalls and perils
As I've said, DFT proves that the electron density as a function of position contains basically  all  the information about the ground state (very cool and very non-obvious).  DFT has become of enormous practical use because one can use simple  noninteracti...
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DFTB3 in GAMESS
I recently did my first DFTB3 calculations in GAMESS.  The process wasn't completely obvious, hence this post. First I got the parameter files from dftb.org .  You have to fill in and email a registration form to get a login so that might take a few days.  ...
I recently did my first DFTB3 calculations in GAMESS. The process wasn't completely obvious, hence this post. First I got the parameter files from dftb.org. You have to fill in and email a registration form to get a login so that might take a few days. I downloaded the 3ob-3-1 parameter set.
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Mia Aim
 
I do have it.
And its pretty compatible with the same academic lectures on that subject.:)

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Molecular Rift: Virtual Reality for Drug Designers
Magnus Norrby, Christoph Grebner, Joakim Eriksson, and Jonas Boström (2015) Contributed by Jan Jensen preview of next version of Molecular Rift now with #Leapmotion sensor attached to the #OculusRift #AugmentedReality pic.twitter.com/5sWmFEsWtS — Jonas Bos...
The Oculus Rift will be available soon making it one of the first generally available virtual reality headset. There are some molecular visualization programs, like iView, that has an "oculus rift button", but that will "just" make the image on the screen look more three dimensional.
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Computational Chemistry Highlights: January issue
The January issue of  Computational Chemistry Highlights  is out. CCH is an  overlay journal  that identifies the most important papers in computational and theoretical chemistry published in the last 1-2 years. CCH is not affiliated with any publisher: it ...
The January issue of Computational Chemistry Highlights is out. CCH is an overlay journal that identifies the most important papers in computational and theoretical chemistry published in the last 1-2 years. CCH is not affiliated with any publisher: it is a free resource run by scientists for ...
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Abstract: We extend our assessment of the potential of perturbative coupled cluster (CC) expansions for a test set of open-shell species to the description of quadruple excitations. In doing so, we compare the prominent CCSDT(Q) and lambda-CCSDT(Q) (a-CCSDT(Q)) models, in which the CC singles, ...
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Sir ,I want to know how to compute CASSCF calculations using GAMESS ..?Apology as well since this is not the relevant place to ask the question. 
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Planned papers for 2016
Just like last year : a plan for the yeat.  Last year I was wildly optimistic with regard to "probable" papers: prediction = 10, actual = 4, so I'll try to be more conservative this time around. Submitted  None Probable 1. Benchmarking of PM6 and DFTB3 for ...
Just like last year: a plan for the yeat. Last year I was wildly optimistic with regard to "probable" papers: prediction = 10, actual = 4, so I'll try to be more conservative this time around. Submitted None Probable 1. Benchmarking of PM6 and DFTB3 for barrier heights computed using enzyme ...
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Have him in circles
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Work
Employment
  • University of Copenhagen
    Professor of Bio-Computational Chemistry, present
  • University of Iowa
    1997 - 2006
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Copenhagen
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Introduction
I am a computational chemist working at the University of Copenhagen.  I work on protein design, quantum chemistry methods, and visualization
Education
  • Iowa State University
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Male