Most DFT domain based speech enhancement methods are dependent on an estimate of the noise power spectral density (PSD). For non-stationary noise sources it is desirable to estimate the noise PSD also in spectral regions where speech is present. In this paper a new method for noise tracking is presented, based on eigenvalue decompositions of correlation matrices that are constructed from time s...

The Polarizable Continuum Model (PCM) can be used in conjunction with Density Functional Theory (DFT) and its time-dependent extension (TDDFT) to simulate the electronic and optical properties of molecules and nanoparticles immersed in a dielectric environment, typically liquid solvents. In this contribution, we develop a methodology to account for solvation effects in real-space (and real-time...

We present the first time-dependent density functional theory (TDDFT) calculation on a light-harvesting triad carotenoid-diaryl-porphyrin-C(60). Besides the numerical challenge that the ab initio study of the electronic structure of such a large system presents, we show that TDDFT is able to provide an accurate description of the excited-state properties of the system. In particular, we calcula...

Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this article we present the ongoing efforts for the parallelisation of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has a great potential for execution in...

Dispersive Fourier Transform (DFT) is a powerful technique for real-time and high-speed spectroscopy. In DFT, the spectral information of an optical pulse is mapped into time using group velocity dispersion (GVD) in the dispersive fibers with an ultrafast real-time spectral acquisition rate (>10 MHz). Typically, multi-mode fiber (MMF) is not recommended for performing DFT because the modal disp...

We propose and consolidate a definition of the discrete fractional Fourier transform that generalizes the discrete Fourier transform (DFT) in the same sense that the continuous fractional Fourier transform generalizes the continuous ordinary Fourier transform. This definition is based on a particular set of eigenvectors of the DFT matrix, which constitutes the discrete counterpart of the set of...

Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this paper we present the ongoing efforts to achieve the parallelization of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has great potential for execution...

The electronic structure relevant to low spin (LS)↔high spin (HS) transitions in Fe(II) coordination compounds with a FeN6 core are studied. The selected [Fe(tz)6]2+ (1) (tz = 1H-tetrazole), [Fe(bipy)3]2+ (2) (bipy = 2,2'-bipyridine), and [Fe(terpy)2]2+ (3) (terpy = 2,2':6',2″-terpyridine) complexes have been actively studied experimentally, and with their respective mono-, bi-, and tridentate ...

Time-dependent orbital-free density functional theory (TD-OFDFT) is an efficient ab-initio method for calculating the electronic dynamics of large systems. In comparison to standard TD-DFT, it computes only a single state regardless system size, but requires additional time-dependent Pauli potential term. We propose nonadiabatic and nonlocal whose main ingredients are particle current densities...