scholarly journals Erratum: “Microscopic observation of the segmental orientation autocorrelation function for entangled and constrained polymer chains” [J. Chem. Phys. 146, 094902 (2017)]

2018 ◽  
Vol 148 (8) ◽  
pp. 089901 ◽  
Author(s):  
Anton Mordvinkin ◽  
Kay Saalwächter
Keyword(s):  
Autocorrelation Function ◽  
Microscopic Observation ◽  
Chem Phys ◽  
Polymer Chains ◽  
Segmental Orientation

Effect of excluded volume on segmental orientation correlations in polymer chains

2008 ◽  
Vol 78 (5) ◽  
Author(s):  
Jens-Uwe Sommer ◽  
Walter Chassé ◽  
Juan López Valentín ◽  
Kay Saalwächter
Keyword(s):  
Polymer Chains ◽  
Excluded Volume ◽  
Segmental Orientation

scholarly journals Molecular structure of azobenzene-containing systems from classical MD simulations

2015 ◽  
Author(s):  
Olga Guskova ◽  
Vladimir Toshchevikov ◽  
Jaroslav Ilnytskyi ◽  
Marina Saphiannikova
Keyword(s):  
Molecular Structure ◽  
Conformational Changes ◽  
Md Simulations ◽  
Chem Phys ◽  
Polymer Chains ◽  
Gyration Radius ◽  
Light Illumination ◽  
Molecular Glasses ◽  
Mesoscopic Level ◽  
Dynamics Simulations

Azobenzene-containing side chain polymers [1,2] and molecular glasses based on propeller-like C3-symmetric azobenzene mesogenes [3] are investigated in classical molecular dynamics simulations. Two length scales are considered: (i) the molecular level with atomistic resolution, where reversible conformational changes of azobenzene chromophores upon light illumination lead to contractions/extensions of low amplitudes due to a limited size of mesogene groups, and (ii) the mesoscopic level, where light-induced molecular movements are observed over larger distances, comparable with the gyration radius of polymer chains. The influence of isomerization and orientation mechanisms on molecular structure and light-induced deformation is elucidated. [1] J. Ilnytskyi et al., J. Chem. Phys. 135, 044901 (2011). [2] M Saphiannikova et al., Proceedings of SPIE "Optical Materials and Biomaterials in Security and Defence Systems Technology X", 8901, 890138 (2013). [3] N.S. Jadavalli et al., Appl. Phys. Lett. 105, 051601 (2014).

scholarly journals FURTHER GENERALIZATION AND NUMERICAL IMPLEMENTATION OF PSEUDO-TIME SCHRÖDINGER EQUATIONS FOR QUANTUM SCATTERING CALCULATIONS

2002 ◽  
Vol 01 (01) ◽  
pp. 1-15 ◽  
Author(s):  
VLADIMIR A. MANDELSHTAM ◽  
ARNOLD NEUMAIER
Keyword(s):  
Schrödinger Equation ◽  
Autocorrelation Function ◽  
Schrodinger Equation ◽  
Bound States ◽  
Sparse Matrix ◽  
Numerical Approach ◽  
Chem Phys ◽  
Numerical Implementation ◽  
Dependent Form ◽  
Energy Dependent

We review and further develop the recently introduced numerical approach [Phys. Rev. Lett. 86, 5031, (2001)] for scattering calculations based on a so called pseudo-time Schrödinger equation, which is in turn a modification of the damped Chebyshev polynomial expansion scheme [J. Chem. Phys. 103, 2903, (1995)]. The method utilizes a special energy-dependent form for the absorbing potential in the time-independent Schrödinger equation, in which the complex energy spectrum is mapped inside the unit disk Ek → uk, where uk are the eigenvalues of some explicitly known sparse matrix U. Most importantly for the numerical implementation, all the physical eigenvalues uk are the extreme eigenvalues of U (i.e. |uk| ≈ 1 for resonances and |uk| = 1 for the bound states), which allows one to extract these eigenvalues very efficiently by harmonic inversion of a pseudo-time autocorrelation function y(t) = ϕ T Ut ϕ using the filter diagonalization method. The computation of y(t) up to time t = 2T requires only T sparse real matrix-vector multiplications. We describe and compare different schemes, effectively corresponding to different choices of the energy-dependent absorbing potential, and test them numerically by calculating resonances of the HCO molecule. Our numerical tests suggest an optimal scheme that provide accurate estimates for most resonance states using a single autocorrelation function.

Sign in / Sign up

Export Citation Format

Share Document