In press, in CrystEngComm (DOI:10.1039/C2CE26523). This is my first full paper completely internet-powered, in that I’ve not physically met any of the other co-authors (also in the internet-powered context, the recent paper on [18]-annulene was written and submitted without sharing a room with Dr. Bruce Hudson, but we’re in the same building, so it doesn’t quite count). Also, one of the few papers for which I had no image generation duties (a rare treat).

The discussion of the very interesting possibilities of molecular redox materials in lithium-ion batteries aside, this paper presents a very thorough example of the power of computational approaches to greatly improve the understanding of solid-state molecular materials by (specifically) 1: overcoming the hydrogen position identification problems inherent in X-ray diffraction methods, 2: reproducing the changes that come with temperature variations in molecular crystals and explaining the origins of those (possibly subtle) changes by way of dispersion-corrected density functional theory, and 3: demonstrating that the nature of intermolecular interactions (specifically hydrogen bonding) can be rigorously cataloged across varied materials using post-optimization tools (in this case, using Carlo Gatti’s excellent TOPOND program).

Gaëtan Bonnard, Anne-Lise Barrès, Olivier Mentré, Damian G. Allis, Carlo Gatti, Philippe Poizot and Christine Frayret^*

Abstract

Following our first experimental and computational study of the room temperature (RT) form of the tetrahydrated 3,6-dihydroxy-2,5-dimethoxy-p-benzoquinone (LiM₂DHDMQ⋅4H₂O) compound, we have researched the occurrence of hydrogen ordering in a new polymorph at lower temperature. The study of polymorphism for the Li₂DHDMQ⋅4H₂O phase employs both experimental (single crystal X-ray diffraction) and theoretical approaches. While clues for disorder over one bridging water molecule were observed at RT (beta-form),a fully ordered model within a supercell has been evidenced at 100K (alpha-form) and is discussed in conjunction with the features characterizing the first polymorphic form reported previously. Density functional theory (DFT) calculations augmented with an empirical dispersion correction (DFT-D) were applied for the prediction of the structural and chemical bonding properties of the alpha and beta polymorphs of Li₂DHDMQ·4H₂O. The relative stability of the two polymorphic systems is evidenced. An insight into the interplay of hydrogen bonding, electrostatic and van der Waals (vdW) interactions in affecting the properties of the two polymorphs is gained. This study also shows how information from DFT-D calculations can be used to augment the information from the experimental crystal diffraction pattern and can so play an active role in crystal structure determination, especially by increasing the reliability and accuracy of H-positioning. These more accurate hydrogen coordinates allowed for a quantification of H-bonding strength through a topological analysis of the electron density (Atoms-in-molecules theory).

I’ve been fortunate twice this year to have the Central New York (CNY) Skeptics force me to commit to a presentation topics I thought were worth presenting. As a complement to the audio that will appear at some point on the CNY Skeptics site, I’ve posted the non-animated slides as a PDF below. And the press photo’s from a way-back Excelsior Cornet Band gig where I had too long a wait between playing and marching.

CNY Skeptics Presents Damian Allis, Ph.D., on “A Most Unlikely Obvious Molecule: DNA And Its Consequences”

Wednesday, November 7, 2012, 7:00 pm
DeWitt Community Library at Shoppingtown Mall
Buckland Community Room

DNA is Nature’s medium of digital information storage and access from which cellular machinery produces life itself. The 60 years of advances in our understanding of DNA have run in parallel with advances in computer technology and information science, and we are now entering an age of whole-genome maps, customized diagnoses, medicines, and dosages from genetic testing, and genetic modification that may eradicate some disorders completely. From super crops to super humans, the genetic information age offers humanity many different possible outcomes. This lecture will cover some of the history, machinery, possibilities, and consequences of DNA life.

Dr. Damian Allis is a research professor in the Department of Chemistry at Syracuse University, research fellow with the Forensic and National Security Sciences Institute, and bioinformaticist for Aptamatrix, Inc. He contains approximately 20 billion miles of DNA.

For those itching for polarizability derivative orientation information and wondering where it is when you ask for it… what’s included below is a combination of a few points in one, specifically pointing out that the IOp options are not just “another part” of the Gaussian input file (with the IOp Overlays currently linked HERE).

The problem I realized after an email from Gaussian HQ was that, as was the case for the KMLYP density functional call discussed in previous posts about [18]-annulene, “opt” and “freq” keyword combinations are seen as two distinct runs in Gaussian that don’t pass the IOp information along (and, admittedly, I should have remembered that). Specifically, the additional print-out for the polarizability info is called by IOp(7/33=3).

What I provide below is a two-in-one input file that saves you from having to run double-duty input files in the checkpoint file. This also serves as a template for those looking for examples of combining multi-step input files that include mixed basis sets (as many of the problems I’ve been emailed stem from carriage return issues more than anything else). Note that the input file is set to run Raman intensities and produce higher-precision (hpmodes) eigenvectors (so, if you just want to test this, remove the “raman”).

%chk=C4H5Cl_B3LYP_631Gdp_LanL2DZ_IR_Raman.chk
#p scf=tight opt=tight b3lyp/GEN pseudo=read

C4H5Cl_B3LYP_631Gdp_LanL2DZ_IR_Raman Opt

0 1
 C                 -1.74671095   -0.64168298    0.00000000
 H                 -1.53944096   -1.69141587    0.00000000
 C                 -0.73010315    0.25446188    0.00000000
 H                 -0.93737314    1.30419477    0.00000000
 C                  0.73010315   -0.25446188    0.00000000
 H                  0.93737314   -1.30419477    0.00000000
 C                  1.74671095    0.64168298    0.00000000
 H                  1.53944096    1.69141587    0.00000000
 H                 -3.73526840    0.03531673    0.00000000
 Cl                 3.73526840   -0.03531673    0.00000000

C H 0
6-31G(d,p)
****
Cl
Lanl2DZ
****

Cl
Lanl2DZ

--Link1--
%chk=C4H5Cl_B3LYP_631Gdp_LanL2DZ_IR_Raman.chk
#p Geom=Check Guess=Read freq(raman,hpmodes) iop(7/33=3)
 
C4H5Cl_B3LYP_631Gdp_LanL2DZ_IR_Raman Freq
     
0 1

Note the carriage return after the second “0 1″.

For the demo molecule above, additional print-out below.

 Dipole derivatives wrt mode   1:  3.96988D-14 -1.15747D-14 -1.96904D-01
 Polarizability derivatives wrt mode          1
                 1             2             3 
      1   0.000000D+00  0.000000D+00  0.206435D+00
      2   0.000000D+00  0.000000D+00  0.143916D-01
      3   0.206435D+00  0.143916D-01  0.000000D+00
 Vibrational polarizability contributions from mode   1       0.0000000       0.0000000       0.0257731
 IFr=  0 A012= 0.23D-23 0.77D+00 0.13D+00 Act= 0.90D+00 DepolP= 0.75D+00 DepolU= 0.86D+00

Alternately, keep track of the checkpoint file.

Minus a few glitches easily fixed with the right software, this build wasn’t bad at all (and thanks to Adam Lindsay for the title catch).

Now sitting in front of a new Core i7 MacBook Pro, one of the first compilations I wanted to have finished for new projects was GROMACS 4.5.5. As my procedure for compiling GROMACS 3.3.3 had been a highly-traveled page, I wanted to provide a brief summary of my successful 4.5.5 compilation.

A Few Piece Of Info

1. XCode

This used to be disc-download and install, now it’s available as a free download from the App Store (1.57 GB download, so plan to do something else while you wait for the download).

2. Homebrew

Having Homebrew installed in Mountain Lion made the installation of FFTW easy and OpenMPI trivial once gfortran was equally trivially installed. Therefore, to make your life easier, I can’t recommend a Homebrew installation enough. For additional install tweaks, I followed the following page: gist.github.com/1860902

Installation Procedure

1. Download gromacs 4.5.5

…and place it in your home folder (will go to Downloads most likely, drag it to your home folder for ease of building).

2. Extract into your home holder

…with a double-click, making ~/gromacs-4.5.5.

3. brew install fftw

With the install of Homebrew, you’ll simply run the following from a terminal window and produce the following output:

brew install fftw

==> Downloading http://www.fftw.org/fftw-3.3.2.tar.gz
######################################################################## 100.0%
==> ./configure --enable-single --enable-sse --enable-shared --disable-debug 
--prefix=/usr/local/Cellar/fftw/3.3.2 --enable-threads --disable-fortran
==> make install
==> make clean
==> ./configure --enable-sse2 --enable-shared --disable-debug 
--prefix=/usr/local/Cellar/fftw/3.3.2 --enable-threads --disable-fortran
==> make install
==> make clean
==> ./configure --enable-long-double --enable-shared --disable-debug 
--prefix=/usr/local/Cellar/fftw/3.3.2 --enable-threads --disable-fortran
==> make install
/usr/local/Cellar/fftw/3.3.2: 34 files, 13M, built in 2.7 minutes

4. brew install gfortran

If you don’t install gfortran FIRST and try to install OpenMPI, you’ll get the following error in Homebrew:

==> Downloading http://www.open-mpi.org/software/ompi/v1.6/downloads/openmpi-1.6.tar.bz2
######################################################################## 100.0%
Error: This formula requires a fortran compiler, but we could not find one by
looking at the FC environment variable or searching your PATH for `gfortran`.
Please take one of the following actions:

  - Decide to use the build of gfortran 4.2.x provided by Homebrew using
        `brew install gfortran`

  - Choose another Fortran compiler by setting the FC environment variable:
        export FC=/path/to/some/fortran/compiler
    Using an alternative compiler may produce more efficient code, but we will
    not be able to provide support for build errors.

So don’t. Installing gfortran will produce the following:

brew install gfortran

==> Downloading http://r.research.att.com/tools/gcc-42-5666.3-darwin11.pkg
######################################################################## 100.0%
==> Installing gfortran 4.2.4 for XCode 4.2 (build 5666) or higher
==> Caveats
Brews that require a Fortran compiler should not use:
  depends_on 'gfortran'

The preferred method of declaring Fortran support is to use:
  def install
    ...
    ENV.fortran
    ...
  end

==> Summary
/usr/local/Cellar/gfortran/4.2.4-5666.3: 86 files, 72M, built in 39 seconds

5. brew install openmpi

This is what allows you to use all cores on your machine and is not in the default XCode install.

brew install openmpi

==> Downloading http://www.open-mpi.org/software/ompi/v1.6/downloads/openmpi-1.6.tar.bz2
Already downloaded: /Library/Caches/Homebrew/open-mpi-1.6.tar.bz2
==> Using Homebrew-provided fortran compiler.
This may be changed by setting the FC environment variable.

==> ./configure --prefix=/usr/local/Cellar/open-mpi/1.6 --enable-ipv6
==> make all
==> make install
/usr/local/Cellar/open-mpi/1.6: 674 files, 21M, built in 5.9 minutes

6. cd gromacs-4.5.5

7. ./configure –enable-float –enable-mpi

You’ll produce output such as found in: 2012august29_gromacs455_configure.txt

You’ll also get two odd errors at the end of the ./configure run that do not affect the rest of the procedure:

./configure --enable-float --enable-mpi

...
./configure: line 29242: sort: No such file or directory
./configure: line 29239: sed: No such file or directory

So ignore them.

NOTE: If you’ve been going by my 3.3.3 procedure and used…

./configure --enable-mpi --enable-double

You’ll get the following error when you try to run make:

Making all in include
Making all in .
make[2]: Nothing to be done for `all-am'.
Making all in types
make[2]: Nothing to be done for `all'.

...

/bin/sh ../../libtool --tag=CC   --mode=compile mpicc -DHAVE_CONFIG_H -I. -I../../src -I/usr/include/libxml2 -I../../include -DGMXLIBDIR=\"/usr/local/gromacs/share/top\"   -O3 -fomit-frame-pointer -finline-functions -Wall -Wno-unused -msse2 -funroll-all-loops -std=gnu99 -MT genborn_sse2_double.lo -MD -MP -MF .deps/genborn_sse2_double.Tpo -c -o genborn_sse2_double.lo genborn_sse2_double.c
 mpicc -DHAVE_CONFIG_H -I. -I../../src -I/usr/include/libxml2 -I../../include -DGMXLIBDIR=\"/usr/local/gromacs/share/top\" -O3 -fomit-frame-pointer -finline-functions -Wall -Wno-unused -msse2 -funroll-all-loops -std=gnu99 -MT genborn_sse2_double.lo -MD -MP -MF .deps/genborn_sse2_double.Tpo -c genborn_sse2_double.c  -fno-common -DPIC -o .libs/genborn_sse2_double.o
genborn_sse2_double.c:931: internal compiler error: Segmentation fault: 11
Please submit a full bug report,
with preprocessed source if appropriate.
See  for instructions.
make[3]: *** [genborn_sse2_double.lo] Error 1
make[2]: *** [all-recursive] Error 1
make[1]: *** [all] Error 2
make: *** [all-recursive] Error 1

So don’t do that, either. The proper flag is the enable-float.

8. make

This will produce the output available for download at: 2012august29_gromacs455_make.txt

9. make install

This will produce the output available for download at: 2012august29_gromacs455_make_install.txt

10. make links

This will produce the short piece of output reproduced below.

cd /usr/local/gromacs/bin && programs=`ls` && cd /usr/local/bin && \
	for i in $programs; do \
	   (test ! -f $i && ln -s /usr/local/gromacs/bin/$i . ; exit 0); \
	done

And with that, you should be able to run all programs from a terminal window.

Blogging a blog post recently blogged here in a post, with a zoom-in below because no decent-sized version of the same can be found on the MedChemComm site, all pertaining to the “Examining the effects of vitamin B12 conjugation on the biological activity of insulin: a molecular dynamic and in vivo oral uptake investigation” article from Susan Clardy-James, myself, Timothy J. Fairchild and Robert P. Doyle in ChemMedComm (available at pubs.rsc.org/en/Content/ArticleLanding/2012/MD/C2MD20040F).

The MedChemComm post also provides the caption for the cover (below), which I reproduce below for context:

Oral delivery of drugs aims to open up new areas of peptide/protein therapeutics associated with the removal for a need for injections. The major problems facing oral delivery of peptides/proteins is hydrolysis/proteolysis in the gastrointestinal tract and an inefficient uptake mechanism for peptides/proteins from the tract. Robert P. Doyle et al. are interested in the use of the vitamin B12 dietary uptake pathway to address these hurdles. In this paper Doyle et al. report the synthesis, purification and characterisation of a new B12-insulin conjugate attached between the B12 ribose hydroxyl group and insulin PheB1.