| 1. |
- Enkovaara, J., et al.
(författare)
-
Electronic structure calculations with GPAW : a real-space implementation of the projector augmented-wave method
- 2010
-
Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 22:25, s. 253202-
-
Forskningsöversikt (refereegranskat)abstract
- Electronic structure calculations have become an indispensable tool in many areas of materials science and quantum chemistry. Even though the Kohn-Sham formulation of the density-functional theory (DFT) simplifies the many-body problem significantly, one is still confronted with several numerical challenges. In this article we present the projector augmented-wave (PAW) method as implemented in the GPAW program package (https://wiki.fysik.dtu.dk/gpaw) using a uniform real-space grid representation of the electronic wavefunctions. Compared to more traditional plane wave or localized basis set approaches, real-space grids offer several advantages, most notably good computational scalability and systematic convergence properties. However, as a unique feature GPAW also facilitates a localized atomic-orbital basis set in addition to the grid. The efficient atomic basis set is complementary to the more accurate grid, and the possibility to seamlessly switch between the two representations provides great flexibility. While DFT allows one to study ground state properties, time-dependent density-functional theory (TDDFT) provides access to the excited states. We have implemented the two common formulations of TDDFT, namely the linear-response and the time propagation schemes. Electron transport calculations under finite-bias conditions can be performed with GPAW using non-equilibrium Green functions and the localized basis set. In addition to the basic features of the real-space PAW method, we also describe the implementation of selected exchange-correlation functionals, parallelization schemes, Delta SCF-method, x-ray absorption spectra, and maximally localized Wannier orbitals.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Tubaro, M., et al.
(författare)
-
Pre-hospital treatment of STEMI patients. A scientific statement of the working group acute cardiac care of the European society of cardiology
- 2011
-
Ingår i: Acute Cardiac Care. - : Informa Healthcare. - 1748-2941 .- 1748-295X. ; 13:2, s. 56-67
-
Tidskriftsartikel (refereegranskat)abstract
- In ST-elevation myocardial infarction (STEMI) the pre-hospital phase is the most critical, as the administration of the most appropriate treatment in a timely manner is instrumental for mortality reduction. STEMI systems of care based on networks of medical institutions connected by an efficient emergency medical service are pivotal. The first steps are devoted to minimize the patients delay in seeking care, rapidly dispatch a properly staffed and equipped ambulance to make the diagnosis on scene, deliver initial drug therapy and transport the patient to the most appropriate (not necessarily the closest) cardiac facility. Primary PCI is the treatment of choice, but thrombolysis followed by coronary angiography and possibly PCI is a valid alternative, according to patients baseline risk, time from symptoms onset and primary PCI-related delay. Paramedics and nurses have an important role in pre-hospital STEMI care and their empowerment is essential to increase the eff ectiveness of the system. Strong cooperation between cardiologists and emergency medicine doctors is mandatory for optimal pre-hospital STEMI care. Scientific societies have an important role in guideline implementation as well as in developing quality indicators and performance measures; health care professionals must overcome existing barriers to optimal care together with political and administrative decision makers.
|
|
| 6. |
- Hao, Xian, et al.
(författare)
-
Direct measurement and modulation of single-molecule coordinative bonding forces in a transition metal complex
- 2013
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Coordination chemistry has been a consistently active branch of chemistry since Werner’s seminal theory of coordination compounds inaugurated in 1893, with the central focus on transition metal complexes. However, control and measurement of metal–ligand interactions at the single-molecule level remain a daunting challenge. Here we demonstrate an interdisciplinary and systematic approach that enables measurement and modulation of the coordinative bonding forces in a transition metal complex. Terpyridine is derived with a thiol linker, facilitating covalent attachment of this ligand on both gold substrate surfaces and gold-coated atomic force microscopy tips. The coordination and bond breaking between terpyridine and osmium are followed in situ by electrochemically controlled atomic force microscopy at the single-molecule level. The redox state of the central metal atom is found to have a significant impact on the metal–ligand interactions. The present approach represents a major advancement in unravelling the nature of metal–ligand interactions and could have broad implications in coordination chemistry.
|
|
