Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set

QUANTUM ESPRESSO is an integrated suite of computer codes for electronic-structure calculations and materials modeling, based on density-functional theory, plane waves, and pseudopotentials (norm-conserving, ultrasoft, and projector-augmented wave). The acronym ESPRESSO stands for opEn Source Package for Research in Electronic Structure, Simulation, and Optimization. It is freely available to researchers around the world under the terms of the GNU General Public License. QUANTUM ESPRESSO builds upon newly-restructured electronic-structure codes that have been developed and tested by some of the original authors of novel electronic-structure algorithms and applied in the last twenty years by some of the leading materials modeling groups worldwide. Innovation and efficiency are still its main focus, with special attention paid to massively parallel architectures, and a great effort being devoted to user friendliness. QUANTUM ESPRESSO is evolving towards a distribution of independent and interoperable codes in the spirit of an open-source project, where researchers active in the field of electronic-structure calculations are encouraged to participate in the project by contributing their own codes or by implementing their own ideas into existing codes.

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QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials

Part I. Fundamental Concepts: 1. Introduction and overview 2. Introduction to quantum mechanics 3. Introduction to computer science Part II. Quantum Computation: 4. Quantum circuits 5. The quantum Fourier transform and its application 6. Quantum search algorithms 7. Quantum computers: physical realization Part III. Quantum Information: 8. Quantum noise and quantum operations 9. Distance measures for quantum information 10. Quantum error-correction 11. Entropy and information 12. Quantum information theory Appendices References Index.

Quantum Computation and Quantum Information

6.2.2. Definition of Effective Properties 3064 6.3. Response Properties to Magnetic Fields 3066 6.3.1. Nuclear Shielding 3066 6.3.2. Indirect Spin−Spin Coupling 3067 6.3.3. EPR Parameters 3068 6.4. Properties of Chiral Systems 3069 6.4.1. Electronic Circular Dichroism (ECD) 3069 6.4.2. Optical Rotation (OR) 3069 6.4.3. VCD and VROA 3070 7. Continuum and Discrete Models 3071 7.1. Continuum Methods within MD and MC Simulations 3072

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Quantum mechanical continuum solvation models.

A digital computer is generally believed to be an efficient universal computing device; that is, it is believed able to simulate any physical computing device with an increase in computation time by at most a polynomial factor. This may not be true when quantum mechanics is taken into consideration. This paper considers factoring integers and finding discrete logarithms, two problems which are generally thought to be hard on a classical computer and which have been used as the basis of several proposed cryptosystems. Efficient randomized algorithms are given for these two problems on a hypothetical quantum computer. These algorithms take a number of steps polynomial in the input size, e.g., the number of digits of the integer to be factored.

Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer

What Is Science

"Everything is interesting if you go into it deeply enough" says Richard P. Feynman in "The Smartest Men in the World", one of the many pieces in this collection of Feynman's best short works. Here we see Feynman as he was - a brilliant physicist who consistently rejected authority, wholeheartedly embraced the value of doubt, and whose infectious sense of curiosity infused everything he did. This wide-ranging collection includes uproarious tales of Feynman's early student experiments (with himself, his socks, his typewriter, his fellow students); his youthful experiences on the Manhattan Project at Los Alamos during World War II; his famous report on the Space Shuttle Challenger disaster; two seminal lectures on the future of computers and nanotechnology; stories of safecracking and plaguing US censors with talcum powder; and tales of the physicist as a child - how his father delighted in showing him the world, and how he, the young boy, took great pleasure in "finding things out".

The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman

There are several reasons to be interested in this problem of very high energy hadron scattering. Firstly, most theoretical inventions are based on analysis of simple collisions, in which only a small number of particles come out. But it is at once realized that questions of unitarity, the asymptotic behavior for high energy in dispersion integrals, etc, require some ansatz be made for the higher energy collisions, in order to close the infinite hierarchy of equations which result. Secondly, experiments at high energies usually yield many particles, and only by selecting the rare collision can we find those about which the theorist has been speaking. For the highly multiple inelastic collisions (to which the major part of the inelastic cross section is due) so many variables are involved that it is not known how to organize or present this data. Any theoretical suggestion (even if it proves to be not quite right) suggests a way that this vast amount of data may be analyzed. For this reason I shall present here some preliminary speculations on how these collisions might behave even though I have not yet analyzed them as fully as I would like.

Behavior of hadron collisions at extreme energies.

A scientist and physicist, one of the greatest of the 20th century, and winner of the Nobel Prize, Richard Feynman worked on the atomic bomb and revealed the cause of the Challenger disaster. Before his death earlier this year, he worked with his friend Ralph Leighton to prepare this manuscript, his last literary legacy. Illustrated.

What Do You Care What Other People Think?: Further Adventures of a Curious Character

Many appreciate Richard P. Feynmans contributions to twentieth-century physics, but few realize how engaged he was with the world around himhow deeply and thoughtfully he considered the religious, political, and social issues of his day. Now, a wonderful bookbased on a previously unpublished, three-part public lecture he gave at the University of Washington in 1963shows us this other side of Feynman, as he expounds on the inherent conflict between science and religion, peoples distrust of politicians, and our universal fascination with flying saucers, faith healing, and mental telepathy. Here we see Feynman in top form: nearly bursting into a Navajo war chant, then pressing for an overhaul of the English language (if you want to know why Johnny cant read, just look at the spelling of friend); and, finally, ruminating on the death of his first wife from tuberculosis. This is quintessential Feynmanreflective, amusing, and ever enlightening.

Richard Phillips Feynman

Papers

What Is Science

The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman

Behavior of hadron collisions at extreme energies.

What Do You Care What Other People Think?: Further Adventures of a Curious Character

The Meaning of It All: Thoughts of a Citizen-Scientist