Alfredo A. Correa

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Explicit integrators for real-time propagation of time-dependent Kohn-Sham equations are compared regarding their suitability for performing large-scale simulations. Four algorithms are implemented and assessed for both stability and accuracy within a plane-wave pseudopotential framework, employing the adiabatic approximation to the exchange-correlation(More)
The Born-Oppenheimer approximation is the keystone for molecular dynamics simulations of radiation damage processes; however, actual materials response involves nonadiabatic energy exchange between nuclei and electrons. In this work, time dependent density functional theory is used to calculate the electronic excitations produced by energetic protons in Al.(More)
Both first-principles molecular dynamics and theoretical X-ray absorption spectroscopy have been used to investigate the aqueous solvation of cations in 0.5 M MgCl(2), CaCl(2), and NaCl solutions. We focus here on the species-specific effects that Mg(2+), Ca(2+), and Na(+) have on the X-ray absorption spectrum of the respective solutions. For the divalent(More)
We show that atomistic first-principles calculations based on real-time propagation within time-dependent density functional theory are capable of accurately describing electronic stopping of light projectile atoms in metal hosts over a wide range of projectile velocities. In particular, we employ a plane-wave pseudopotential scheme to solve time-dependent(More)
This study was conducted to investigate the effects of two major ingredients in cigarette smoke, benzo-alpha-pyrene (BP) and nicotine (Nic), on epidermal growth factor (EGF) receptor in hamster buccal pouch. Adult male Syrian hamsters were treated by apically swabbing the buccal pouch with mineral oil (Control), 0.5 microgram/ml of BP, Nic or BP+Nic in(More)
At high pressure and temperature, the phase diagram of elemental carbon is poorly known. We present predictions of diamond and BC8 melting lines and their phase boundary in the solid phase, as obtained from first-principles calculations. Maxima are found in both melting lines, with a triple point located at approximately 850 GPa and approximately 7,400 K.(More)
We use time-resolved x-ray absorption spectroscopy to investigate the unoccupied electronic density of states of warm dense copper that is produced isochorically through the absorption of an ultrafast optical pulse. The temperature of the superheated electron-hole plasma, which ranges from 4000 to 10 000 K, was determined by comparing the measured x-ray(More)
Advancement in high-performance computing allows us to calculate properties of increasingly complex materials with unprecedented accuracy. At the same time, to take full advantage of modern leadership-class supercomputers, the calculations need to scale well on hundreds of thousands of processing cores. We demonstrate such high scalability of our recently(More)
Prostaglandin E2 (PGE2) plays an important role in the maintenance of oral mucosal integrity. In this study, we characterized PGE2 receptor binding in the buccal mucosa of Syrian hamster and assessed the effect of nicotine (NC) and benzo (a) pyrene (BP), the two major ingredients in cigarette smoke, on this receptor. Adult male animals were treated for 4(More)
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. We present a 5-phase equation of state for elemental carbon which addresses a(More)