Sökning: "quantum chemistry calculation"

Visar resultat 1 - 5 av 34 avhandlingar innehållade orden quantum chemistry calculation.

1. 1. Synthesis and development of compounds for nonlinear absorption of light

   Författare :Tomas Kindahl; Bertil Eliasson; Sascha Ott; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Platinum acetylide; nonlinear absorption; optical power limiting; oxazole; quantum chemistry calculation; quantum chemical calculation; triplet absorption; organisk kemi; Organic Chemistry; fysikalisk kemi; Physical Chemistry; Quantum Chemistry; kvantkemi;

   Sammanfattning : High-intensity light — for instance that from a laser — can be destructive, not only to the human eye, but also to equipment such as imaging sensors and optical communication devices. Therefore, effective protection against such light is desirable. LÄS MER

3. 2. Quantum Chemical Interpretation of Protein Crystal Structure

   Författare :Kristina Nilsson; Beräkningskemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; structure; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi; protein; ComQum-X; Hess2FF; QM MM; hetero-compound; metal; oxidation state; protonation; force field; quantum refinement; refinement;

   Sammanfattning : An initial model in the crystallographic structure determination process, usually contains many errors. To produce an accurate model, one must carry out several cycles of crystallographic refinement. LÄS MER

4. 3. Quantum dynamical effects in complex chemical systems

   Författare :S. Karl-Mikael Svensson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum dynamics; Radiative association; Classical Wigner method; Feynman path integral; Reaction rate constants; Wigner phase space;

   Sammanfattning : When using mathematical models to computationally investigate a chemical system it is important that the methods used are accurate enough to account for the relevant properties of the system and at the same time simple enough to be computationally affordable. This thesis presents research that so far has resulted in three published papers and one unpublished manuscript. LÄS MER

5. 4. Matrix Algebra for Quantum Chemistry

   Författare :Emanuel H. Rubensson; Pawel Salek; Stefan Goedecker; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; linear scaling; reduced complexity; electronic structure; density functional theory; Hartree-Fock; density matrix purification; congruence transformation; inverse factorization; eigenvalues; eigenvectors; numerical linear algebra; occupied subspace; canonical angles; invariant subspace; Theoretical chemistry; Teoretisk kemi;

   Sammanfattning : This thesis concerns methods of reduced complexity for electronic structure calculations.  When quantum chemistry methods are applied to large systems, it is important to optimally use computer resources and only store data and perform operations that contribute to the overall accuracy. LÄS MER

7. 5. Theoretical Studies of Cytochrome P450

   Författare :Patrik Rydberg; Beräkningskemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; Proteins; enzymology; Proteiner; enzymologi; Theoretical chemistry; transition-state force field; peroxidase; theoretical chemistry; molecular dynamics; density functional theory; cytochrome P450; porphyrin; haem; heme; kvantkemi; Teoretisk kemi;

   Sammanfattning : The cytochromes P450 are a large enzyme family that is found in all living organisms and takes part in both endogenous and exogenous metabolism. They are primarily mono-oxygenases and perform a wide range of reactions. LÄS MER