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We present a variational function that targets excited states directly based on their position in the energy spectrum, along with a Monte Carlo method for its evaluation and minimization whose cost scales polynomially for a wide class of…

Strongly Correlated Electrons · Physics 2016-01-22 Luning Zhao , Eric Neuscamman

Density functional calculations of Rydberg excited states up to high energy are carried out for several molecules using an approach where the orbitals are variationally optimized by converging on saddle points on the electronic energy…

We employ a generalized variational principle to improve the stability, reliability, and precision of fully excited-state-specific complete active space self-consistent field theory. Compared to previous approaches that similarly seek to…

Chemical Physics · Physics 2022-09-05 Rebecca Hanscam , Eric Neuscamman

The optimization of low-thrust, multi-revolution orbit transfer trajectories is often regarded as a difficult problem in modern astrodynamics. In this paper, a flexible and computationally efficient approach is presented for the…

Optimization and Control · Mathematics 2024-09-11 Mirko Leomanni , Gianni Bianchini , Andrea Garulli , Renato Quartullo

We present a general approach to converge excited state solutions to any quantum chemistry orbital optimization process, without the risk of variational collapse. The resulting Square Gradient Minimization (SGM) approach only requires…

Chemical Physics · Physics 2020-03-11 Diptarka Hait , Martin Head-Gordon

The excited electronic states involved in the optical cycle preparation of a pure spin state of the negatively charged NV-defect in diamond are calculated using the HSE06 hybrid density functional and variational optimization of the…

Materials Science · Physics 2025-10-29 Lei Sun , Elvar Örn Jónsson , Aleksei Ivanov , Ji Chen , Hannes Jónsson

We present a simple and efficient wave function ansatz for the treatment of excited charge-transfer states in real-space quantum Monte Carlo methods. Using the recently-introduced variation-after-response method [J. Chem. Phys. 145, 081103…

Chemical Physics · Physics 2017-11-20 N. S. Blunt , Eric Neuscamman

The choice of molecular orbitals is decisive in configuration interaction calculations. In this letter, a democratic description of the ground and excited states follows an orthogonally constrained orbitals optimization to produce…

Quantum Physics · Physics 2023-02-16 Saad Yalouz , Vincent Robert

Calculations of highly excited and delocalized molecular vibrational states are computationally challenging tasks, which strongly depends on the choice of coordinates for describing vibrational motions. We introduce a new method that…

Intermolecular charge-transfer is a highly important process in biology and energy-conversion applications where generated charges need to be transported over several moieties. However, its theoretical description is challenging since the…

Chemical Physics · Physics 2024-05-03 Nicola Bogo , Christopher J. Stein

In this paper we study the problem of designing periodic orbits for a special class of hybrid systems, namely mechanical systems with underactuated continuous dynamics and impulse events. We approach the problem by means of optimal control.…

Optimization and Control · Mathematics 2017-02-16 Sara Spedicato , Giuseppe Notarstefano

Quantum--Mechanical methods that are both computationally fast and accurate are not yet available for electronic excitations having charge transfer character. In this work, we present a significant step forward towards this goal for those…

Chemical Physics · Physics 2015-06-12 Michele Pavanello , Troy Van Voorhis , Lucas Visscher , Johannes Neugebauer

The limitations of centralized optimization methods in managing power distribution systems operations motivate distributed control and optimization algorithms. However, the existing distributed optimization algorithms are inefficient in…

Optimization and Control · Mathematics 2021-09-06 Rabayet Sadnan , Tom Asaki , Anamika Dubey

We present an approach for accurate calculation of exchange energy and total energy for excited states using time independent density functional formalism. This is done by inclusion of gradient correction into the excited state exchange…

Chemical Physics · Physics 2012-01-31 Md. Shamim , Manoj K. Harbola

We consider a direct optimization approach for ensemble density functional theory electronic structure calculations. The update operator for the electronic orbitals takes the structure of the Stiefel manifold into account and we present an…

Computational Physics · Physics 2012-07-11 K. Baarman , V. Havu , T. Eirola

An energy functional for orbital based $O(N)$ calculations is proposed, which depends on a number of non orthogonal, localized orbitals larger than the number of occupied states in the system, and on a parameter, the electronic chemical…

mtrl-th · Physics 2016-09-07 Jeongnim Kim , Francesco Mauri , Giulia Galli

Biomolecular machines transduce between different forms of energy. These machines make directed progress and increase their speed by consuming free energy, typically in the form of nonequilibrium chemical concentrations. Machine dynamics…

Statistical Mechanics · Physics 2018-10-05 Aidan I Brown , David A Sivak

We present a reduced-cost equation-of-motion coupled-cluster method for excited states, built on a new state-specific frozen natural orbital (SS-FNO) framework. This approach enables systematic and controllable truncation of the virtual…

Chemical Physics · Physics 2025-07-24 Amrita Manna , Achintya Kumar Dutta

The authors present a technique using variational Monte Carlo to solve for excited states of electronic systems. The technique is based on enforcing orthogonality to lower energy states, which results in a simple variational principle for…

Chemical Physics · Physics 2021-10-15 Shivesh Pathak , Brian Busemeyer , João N. B. Rodrigues , Lucas K. Wagner

The problem of optimal control of power distribution systems is becoming increasingly compelling due to the progressive penetration of distributed energy resources in this specific layer of the electrical infrastructure. Distribution…

Systems and Control · Computer Science 2016-11-17 Konstantina Christakou , Jean-Yves Le Boudec , Mario Paolone , Dan-Cristian Tomozei