%%%%%%%%%%%%%%

ARTICLE

%% %%%%%%%%%%%%%%%%%%%

\documentclass[8pt,a4paper]{scrartcl} \usepackage[top=2.5cm,bottom=2.5cm,left=2cm,right=2cm]{geometry} \usepackage{amsmath} \usepackage{cancel} \usepackage{graphicx} \usepackage{mathcomp} \usepackage{ngerman} \usepackage{braket} \usepackage{multicol} \usepackage[applemac]{inputenc} \usepackage{color} \usepackage{shadow} \usepackage{times} \usepackage[superscript,nospace]{cite} \usepackage{booktabs} \usepackage{fancyhdr} \fancyhead[R]{\includegraphics[height=0.7cm]{junq_3_klein}} \fancyhead[C]{\emph{Articles}} \fancyhead[L]{\small{TITLE}}%%%%%%%%%% <= PUT YOUR TITLE HERE AGAIN \fancyfoot[CE,CO] {\thepage} \fancyfoot[LE,RO]{CITATION DETAILS} \fancyfoot[RE,LO]{} \pagestyle{fancy} \begin{document} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%% %%%% THIS IS A TEMPLATE FOR AN ARTICLE IN THE JOURNAL OF UNSOLVED QUESTIONS. IF YOU CHANGE THE TEMPLATE'S SETTINGS (FONTSTYLE, FONTSIZE, HEADER, FOOTER, COLUMNS,LAYOUT IN GENERAL) YOUR SUBMISSION WILL NOT BE ACCEPTED. YOU MAY ADD MORE USEPACKAGES AS YOU PLEASE. YOU ALSO NEED TO DOWNLOAD THE LOGO AND ADD IT TO THE FOLDER OF YOUR TEX DOCUMENTS %%%%%%%%%%%%%%% %%%%% THE ARTICLE CAN BE AT MOST 4 PAGES LONG %%%%%%%%%%%%%%% %%%%%%%%% TITLE SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%% \begin{center} ~ \vspace{0.7cm}\\ {\Large{\bf Title}} \\ %<==put the title here \medskip {\bf{\underline{Author 1}\footnote{Affiliation of Author 1}}, Author 2\footnote{Affiliation of Author 2} }\\ {\emph{Institution, City and Country of first author}}\medskip\\ %<== put the authors here, centered, with the name of the first author underlined. Use 12-Point boldface Times New Roman typeface. Superscript number refers to author's affiliation {Received 00.00.2010, accepted 00. 00. 2010, published 00.00.2010} \bigskip \end{center} %%%%%%%%%%%%%%%%%%%% ABSTRACT %%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{center} \begin{minipage}[c]{0.7\textwidth} Put your abstract here: Coupled-cluster theory in its single-reference formulation (SRCC) is one of the most accurate and powerful methods for solving the nonrelativistic electronic Schrรถdinger equation for atoms and molecules as it adequately accounts for dynamic electron correlation. It fails, though, for multireference cases like excited states, biradicals and for systems with degenerate or quasidegenerate states \end{minipage}

\end{center} \bigskip

% %%%%%%%%%%%%%%%%% BEGINNING ARTICLE%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{multicols}{2} \section{Section 1} Coupled-cluster theory in its single-reference formulation (SRCC) is one of the most accurate and powerful methods for solving the nonrelativistic electronic Schrödinger equation for atoms and molecules as it adequately accounts for dynamic electron correlation. It fails, though, for multireference cases like excited states, biradicals and for systems with degenerate or quasidegenerate states For these cases with static electron correlation the use of a multireference method is required. Among the plethora of multireference coupled-cluster formulations Mukherjee’s multireference coupled-cluster method (Mk-MRCC) has proven to be promising [1,2]. Especially the property of size-extensivity determines the success of Mk-MRCC. Nevertheless Mk-MRCC is still highly experimental and several theoretical aspects are yet uncertain, among them the concern, that the corresponding reference determinants might not be sufficiently coupled in the Mk-MRCC ansatz. During my PhD I want to exploit the Mk-MRCC ansatz to calculate spin-orbit (SO) splittings in degenerate open-shell $\Pi$-states. For these molecules the exact treatment of SO couplings is essential (even if they contain only light elements like e. g. OH) for the high-accuracy computation of spectra and thermochemical parameters. It is planned to connect the computation of SO splittings with scalar-relativistic calculations (direct perturbation theory [4]), which will enable a thorough treatment of relativistic effects in molecules containing light elements. Furthermore SO splittings can serve as a quality criterion for the coupling terms and sufficiency conditions in Mk-MRCC theory since the SO operator directly couples the corresponding reference determinants. Considering theoretical aspects and comparing the obtained SO splittings with experimental data we want to examine Mk-MRCC theory and - if indicated - propose improvements. My current research questions are: \begin{itemize} \item{How can Mk-MRCC SO-splittings be optimally calculated?} \item{Based on the evaluation of SO-splittings which conclusions can we draw regarding the quality of MkMRCC theory?} \item{How could the Mk-MRCC be improved?} \item{How can the computation of SO-splittings be connected with existing implementations of directperturbation theory?} \end{itemize} \section{Section 2} In the following I would like to give a summary of the contemplations and achievements of the past six months. I have listed the milestones that proved to be important for the progress of my project and for my deeper understanding of the subject. \subsection{Subsection 2.1} blabla Coupled-cluster theory in its single-reference formulation (SRCC) is one of the most accurate and powerful methods for solving the nonrelativistic electronic Schrödinger equation for atoms and molecules as it adequately accounts for dynamic electron correlation. It fails, though, for multireference cases like excited states, biradicals and for systems with degenerate or quasidegenerate states For these cases with static electron correlation the use of a multireference method is required. Among the plethora of multireference coupled-cluster formulations Mukherjee’s multireference coupled-cluster method (Mk-MRCC) has proven to be promising [1,2]. Especially the property of size-extensivity determines the success of Mk-MRCC. Nevertheless Mk-MRCC is still highly experimental and several theoretical aspects are yet uncertain, among them the concern, that the corresponding reference determinants might not be sufficiently coupled in the Mk-MRCC ansatz. During my PhD I want to exploit the Mk-MRCC ansatz to calculate spin-orbit (SO) splittings in degenerate open-shell $\Pi$-states. For these molecules the exact treatment of SO couplings is essential (even if they

contain only light elements like e. g. OH) for the high-accuracy computation of spectra and thermochemical parameters. It is planned to connect the computation of SO splittings with scalar-relativistic calculations (direct perturbation theory [4]), which will enable a thorough treatment of relativistic effects in molecules containing light elements. Furthermore SO splittings can serve as a quality criterion for the coupling terms and sufficiency conditions in Mk-MRCC theory since the SO operator directly couples the corresponding reference determinants. Considering theoretical aspects and comparing the obtained SO splittings with experimental data we want to examine Mk-MRCC theory and - if indicated - propose improvements. My current research questions are: \begin{itemize} \item{How can Mk-MRCC SO-splittings be optimally calculated?} \item{Based on the evaluation of SO-splittings which conclusions can we draw regarding the quality of MkMRCC theory?} \item{How could the Mk-MRCC be improved?} \item{How can the computation of SO-splittings be connected with existing implementations of directperturbation theory?} \end{itemize} Coupled-cluster theory in its single-reference formulation (SRCC) is one of the most accurate and powerful methods for solving the nonrelativistic electronic Schrödinger equation for atoms and molecules as it adequately accounts for dynamic electron correlation. It fails, though, for multireference cases like excited states, biradicals and for systems with degenerate or quasidegenerate states For these cases with static electron correlation the use of a multireference method is required. Among the plethora of multireference coupled-cluster formulations Mukherjee’s multireference coupled-cluster method (Mk-MRCC) has proven to be promising [1,2]. Especially the property of size-extensivity determines the success of Mk-MRCC. Nevertheless Mk-MRCC is still highly experimental and several theoretical aspects are yet uncertain, among them the concern, that the corresponding reference determinants might not be sufficiently coupled in the Mk-MRCC ansatz. During my PhD I want to exploit the Mk-MRCC ansatz to calculate spin-orbit (SO) splittings in degenerate open-shell $\Pi$-states. For these molecules the exact treatment of SO couplings is essential (even if they contain only light elements like e. g. OH) for the high-accuracy computation of spectra and thermochemical parameters. It is planned to connect the computation of SO splittings with scalar-relativistic calculations (direct perturbation theory [4]), which will enable a thorough treatment of relativistic effects in molecules containing light elements. Furthermore SO splittings can serve as a quality criterion for the coupling terms and sufficiency conditions in Mk-MRCC theory since the SO operator directly couples the corresponding reference determinants. Considering theoretical aspects and comparing the obtained SO splittings with experimental data we want to examine Mk-MRCC theory and - if indicated - propose improvements. My current research questions are: \begin{itemize} \item{How can Mk-MRCC SO-splittings be optimally calculated?} \item{Based on the evaluation of SO-splittings which conclusions can we draw regarding the quality of MkMRCC theory?} \item{How could the Mk-MRCC be improved?} \item{How can the computation of SO-splittings be connected with existing implementations of directperturbation theory?} \end{itemize} Coupled-cluster theory in its single-reference formulation (SRCC) is one of the most accurate and powerful methods for solving the nonrelativistic electronic Schrödinger equation for atoms and molecules as it adequately accounts for dynamic electron correlation. It fails, though, for multireference cases like excited states, biradicals and for systems with degenerate or quasidegenerate states For these cases with static electron correlation the use of a multireference method is required. Among the plethora of multireference coupled-cluster formulations Mukherjee’s multireference coupled-cluster method (Mk-MRCC) has proven to be promising [1,2]. Especially the property of size-extensivity determines the success of Mk-MRCC. Nevertheless Mk-MRCC is still highly experimental and several theoretical aspects are yet uncertain, among them the concern, that the corresponding reference determinants might not be sufficiently coupled in the Mk-MRCC ansatz.

During my PhD I want to exploit the Mk-MRCC ansatz to calculate spin-orbit (SO) splittings in degenerate open-shell $\Pi$-states. For these molecules the exact treatment of SO couplings is essential (even if they contain only light elements like e. g. OH) for the high-accuracy computation of spectra and thermochemical parameters. It is planned to connect the computation of SO splittings with scalar-relativistic calculations (direct perturbation theory [4]), which will enable a thorough treatment of relativistic effects in molecules containing light elements. Furthermore SO splittings can serve as a quality criterion for the coupling terms and sufficiency conditions in Mk-MRCC theory since the SO operator directly couples the corresponding reference determinants. Considering theoretical aspects and comparing the obtained SO splittings with experimental data we want to examine Mk-MRCC theory and - if indicated - propose improvements. My current research questions are: \begin{itemize} \item{How can Mk-MRCC SO-splittings be optimally calculated?} \item{Based on the evaluation of SO-splittings which conclusions can we draw regarding the quality of MkMRCC theory?} \item{How could the Mk-MRCC be improved?} \item{How can the computation of SO-splittings be connected with existing implementations of directperturbation theory?} \end{itemize}

%%%%%%%%%%%%%%%%%% LITERATURE %%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%% \vspace{1cm} \parindent=0pt \small{[1] U. S. Mahapatra, B. Datta and D. Mukherjee, \emph{Mol. Phys.} 94 (1998) 157-171.}\\ \small{[2] F. A. Evangelista, W. D. Allen and H. F. Schaefer III, \emph{J. Chem. Phys} 127 (2007) 024102.}\\ \small{[3] E. Prochnow, F.A. Evangelista, H.F. Schaefer III, W.D. Allen and J. Gauss, \emph{J. Chem. Phys.} 131 (2009) 064109/1-12. }\\ \small{[4] S. Stopkowicz and J. Gauss, \emph{J. Chem. Phys} 129 (2008) 164119/1-9.}\\ \small{[5] \emph{see www.cfour.de}}\\ \end{multicols} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%% \end{document}