Theory and Simulation

Group Leader: Pablo Ordejón

Pablo Ordejón

Distinguished Researcher, Group Leader and Director

Group Leader

Prof. Pablo Ordejón earned his degree in physics (1987) and his PhD in science (1992) at the Universidad Autónoma de Madrid. He worked as a postdoctoral researcher at the University of Illinois at Urbana-Champaign (USA) from 1992 to 1995 and as assistant professor at the Universidad de Oviedo from 1995 to 1999. In 1999, he obtained a research staff position at the Institut de Ciència de Materials de Barcelona of the Consejo Superior de Investigaciones Científicas (CSIC). In 2007 he moved to the former CIN2 (now ICN2) as the leader of the Theory and Simulation Group, where he is currently a CSIC Research Professor. Since July 2012 he has served as Director of the ICN2.

He has published more than 210 scientific articles, which have received over 30,000 citations (h-index of 59). He was co-editor of EPL (formerly Euro Physics Letters) from 2010 to 2015, and is member of the Editorial Boards of the Physica Status Solidi journals since 2004 and Nanomaterials since 2018.

He oversaw the Condensed Matter Physics subject area of the Physics Panel of the Spanish National Evaluation and Foresight Agency (ANEP) from 2003 to 2006, and was the head of the Physics and Engineering Panel of the Access Committee to the Spanish Supercomputing Network from 2005 to 2011. He became a fellow of the American Physical Society in 2005, and received the Narcís Monturiol medal from the Catalan Government in 2018.

His research is focused on the development of efficient methods for electronic structure calculations in large and complex systems, with contributions to the development of techniques for large-scale atomistic simulations based on first-principles methods such as SIESTA. He has also been involved in the study of the fundamental properties of materials at the atomistic level. His current interests include electronic transport in nanoscale devices and electronic processes at surfaces and 2D materials, among many others. He maintains frequent collaborations with industrial laboratories on the simulation of material processes at the atomic level. He is a co-founder of the spinoff company SIMUNE.



  • Atomically Sharp Lateral Superlattice Heterojunctions Built-In Nitrogen-Doped Nanoporous Graphene

    Tenorio M., Moreno C., Febrer P., Castro-Esteban J., Ordejón P., Peña D., Pruneda M., Mugarza A. Advanced Materials; 34 (20, 2110099) 2022. 10.1002/adma.202110099. IF: 30.849

  • Colossal phonon drag enhanced thermopower in lightly doped diamond

    Li C., Protik N.H., Ordejón P., Broido D. Materials Today Physics; 27 (100740) 2022. 10.1016/j.mtphys.2022.100740.

  • Competition between Ta-Ta and Te-Te bonding leading to the commensurate charge density wave in TaTe4

    Guster B., Pruneda M., Ordejón P., Canadell E. Physical Review B; 105 (6, 064107) 2022. 10.1103/PhysRevB.105.064107. IF: 4.036

  • Interference effects in one-dimensional moiré crystals

    Wittemeier N., Verstraete M.J., Ordejón P., Zanolli Z. Carbon; 186: 416 - 422. 2022. 10.1016/j.carbon.2021.10.028. IF: 9.594

  • Magnetic properties of coordination clusters with {Mn4} and {Co4} antiferromagnetic cores

    Achilli S., Besson C., He X., Ordejón P., Meyer C., Zanolli Z. Physical Chemistry Chemical Physics; 24 (6): 3780 - 3787. 2022. 10.1039/d1cp03904k. IF: 3.676

  • Manipulation of spin transport in graphene/transition metal dichalcogenide heterobilayers upon twisting

    Pezo A., Zanolli Z., Wittemeier N., Ordejón P., Fazzio A., Roche S., Garcia J.H. 2D Materials; 9 (1, 015008) 2022. 10.1088/2053-1583/ac3378. IF: 7.103

  • The elphbolt ab initio solver for the coupled electron-phonon Boltzmann transport equations

    Protik N.H., Li C., Pruneda M., Broido D., Ordejón P. npj Computational Materials; 8 (1, 28) 2022. 10.1038/s41524-022-00710-0. IF: 12.241

  • Tuning the topological band gap of bismuthene with silicon-based substrates

    Wittemeier N., Ordejón P., Zanolli Z. JPhys Materials; 5 (3, 035002) 2022. 10.1088/2515-7639/ac84ad.

  • Unraveling Heat Transport and Dissipation in Suspended MoSe2 from Bulk to Monolayer

    Saleta Reig D., Varghese S., Farris R., Block A., Mehew J.D., Hellman O., Woźniak P., Sledzinska M., El Sachat A., Chávez-Ángel E., Valenzuela S.O., van Hulst N.F., Ordejón P., Zanolli Z., Sotomayor Torres C.M., Verstraete M.J., Tielrooij K.-J. Advanced Materials; 34 (10, 2108352) 2022. 10.1002/adma.202108352. IF: 30.849


  • Basic aspects of the charge density wave instability of transition metal trichalcogenides NbSe3and monoclinic-TaS3

    Guster B., Pruneda M., Ordejón P., Canadell E., Pouget J.-P. Journal of Physics Condensed Matter; 33 (48, 485401) 2021. 10.1088/1361-648X/ac238a. IF: 2.333

  • Validity of the on-site spin-orbit coupling approximation

    Cuadrado R., Robles R., García A., Pruneda M., Ordejón P., Ferrer J., Cerdá J.I. Physical Review B; 104 (19, 195104) 2021. 10.1103/PhysRevB.104.195104. IF: 4.036


  • Anion ordering transition and Fermi surface electron-hole instabilities in the (TMTSF)2ClO4and (TMTSF)2NO3Bechgaard salts analyzed through the first-principles Lindhard response function

    Guster B., Pruneda M., Ordejón P., Canadell E., Pouget J.-P. Journal of Physics Condensed Matter; 33 (8, 085705) 2020. 10.1088/1361-648X/abc406. IF: 2.705

  • Fermi surface electron-hole instability of the (TMTSF)2PF6 Bechgaard salt revealed by the first-principles Lindhard response function

    Guster B., Pruneda M., Ordejón P., Canadell E., Pouget J.-P. Journal of Physics Condensed Matter; 32 (34, 345701) 2020. 10.1088/1361-648X/ab8522. IF: 2.707

  • Siesta: Recent developments and applications

    García A., Papior N., Akhtar A., Artacho E., Blum V., Bosoni E., Brandimarte P., Brandbyge M., Cerdá J.I., Corsetti F., Cuadrado R., Dikan V., Ferrer J., Gale J., García-Fernández P., García-Suárez V.M., García S., Huhs G., Illera S., Korytár R., Koval P., Lebedeva I., Lin L., López-Tarifa P., Mayo S.G., Mohr S., Ordejón P., Postnikov A., Pouillon Y., Pruneda M., Robles R., Sánchez-Portal D., Soler J.M., Ullah R., Yu V.W.-Z., Junquera J. The Journal of chemical physics; 152 (20): 204108. 2020. 10.1063/5.0005077. IF: 2.991


  • 2 × 2 charge density wave in single-layer TiTe2

    Guster B., Robles R., Pruneda M., Canadell E., Ordejón P. 2D Materials; 6 (1, 015027) 2019. 10.1088/2053-1583/aaf20b. IF: 7.343

  • Coexistence of Elastic Modulations in the Charge Density Wave State of 2 H-NbSe 2

    Guster B., Rubio-Verdú C., Robles R., Zaldívar J., Dreher P., Pruneda M., Silva-Guillén J.Á., Choi D.-J., Pascual J.I., Ugeda M.M., Ordejón P., Canadell E. Nano Letters; 19 (5): 3027 - 3032. 2019. 10.1021/acs.nanolett.9b00268. IF: 12.279

  • Evidence for the weak coupling scenario of the Peierls transition in the blue bronze

    Guster B., Pruneda M., Ordejón P., Canadell E., Pouget J.-P. Physical Review Materials; 3 (5, 055001) 2019. 10.1103/PhysRevMaterials.3.055001. IF: 2.926


  • Addressing the Environment Electrostatic Effect on Ballistic Electron Transport in Large Systems: A QM/MM-NEGF Approach

    Feliciano G.T., Sanz-Navarro C., Coutinho-Neto M.D., Ordejón P., Scheicher R.H., Rocha A.R. Journal of Physical Chemistry B; 122 (2): 485 - 492. 2018. 10.1021/acs.jpcb.7b03475. IF: 3.146

  • First principles analysis of the CDW instability of single-layer 1T-TiSe2 and its evolution with charge carrier density

    Guster B., Canadell E., Pruneda M., Ordejón P. 2D Materials; 5 (2, 025024) 2018. 10.1088/2053-1583/aab568. IF: 7.042

  • Implementation of non-collinear spin-constrained DFT calculations in SIESTA with a fully relativistic Hamiltonian

    R. Cuadrado, M. Pruneda, A. García, P. Ordejón Journal of Physics: Materials; 1 (1) 2018. 10.1088/2515-7639/aae7db.

  • Mechanisms behind the enhancement of thermal properties of graphene nanofluids

    Rodríguez-Laguna M.R., Castro-Alvarez A., Sledzinska M., Maire J., Costanzo F., Ensing B., Pruneda M., Ordejón P., Sotomayor Torres C.M., Gómez-Romero P., Chávez-Ángel E. Nanoscale; 10 (32): 15402 - 15409. 2018. 10.1039/c8nr02762e. IF: 7.233

  • Spin Proximity Effects in Graphene/Topological Insulator Heterostructures

    Song K., Soriano D., Cummings A.W., Robles R., Ordejón P., Roche S. Nano Letters; 18 (3): 2033 - 2039. 2018. 10.1021/acs.nanolett.7b05482. IF: 12.080


  • Ab initio study of electron-phonon coupling in rubrene

    Ordejón P., Boskovic D., Panhans M., Ortmann F. Physical Review B; 96 (3, 035202) 2017. 10.1103/PhysRevB.96.035202. IF: 3.836

  • Anisotropic features in the electronic structure of the two-dimensional transition metal trichalcogenide TiS3: Electron doping and plasmons

    Silva-Guillén J.A., Canadell E., Ordejón P., Guinea F., Roldán R. 2D Materials; 4 (2, 025085) 2017. 10.1088/2053-1583/aa6b92. IF: 6.937

  • Growth of Twin-Free and Low-Doped Topological Insulators on BaF2(111)

    Bonell F., Cuxart M.G., Song K., Robles R., Ordejón P., Roche S., Mugarza A., Valenzuela S.O. Crystal Growth and Design; 17 (9): 4655 - 4660. 2017. 10.1021/acs.cgd.7b00525. IF: 4.055

  • Thermal and transport properties of pristine single-layer hexagonal boron nitride: A first principles investigation

    Sergio Illera, Miguel Pruneda, Luciano Colombo, Pablo Ordejón Physical Review Materials; 1 (4): 44006. 2017. 10.1103/PhysRevMaterials.1.044006.

  • Voltage-Induced Coercivity Reduction in Nanoporous Alloy Films: A Boost toward Energy-Efficient Magnetic Actuation

    Quintana A., Zhang J., Isarain-Chávez E., Menéndez E., Cuadrado R., Robles R., Baró M.D., Guerrero M., Pané S., Nelson B.J., Müller C.M., Ordejón P., Nogués J., Pellicer E., Sort J. Advanced Functional Materials; 27 (32, 1701904) 2017. 10.1002/adfm.201701904. IF: 12.124


  • Electronic structure of 2H-NbSe2 single-layers in the CDW state

    Silva-Guillén J.Á., Ordejón P., Guinea F., Canadell E. 2D Materials; 3 (3, 035028) 2016. 10.1088/2053-1583/3/3/035028. IF: 9.611

  • How disorder affects topological surface states in the limit of ultrathin Bi2Se3 films

    Song K., Soriano D., Robles R., Ordejon P., Roche S. 2D Materials; 3 (4, 045007) 2016. 10.1088/2053-1583/3/4/045007. IF: 9.611

  • Nanotexturing to Enhance Photoluminescent Response of Atomically Thin Indium Selenide with Highly Tunable Band Gap

    Brotons-Gisbert M., Andres-Penares D., Suh J., Hidalgo F., Abargues R., Rodríguez-Cantó P.J., Segura A., Cros A., Tobias G., Canadell E., Ordejón P., Wu J., Martínez-Pastor J.P., Sánchez-Royo J.F. Nano Letters; 16 (5): 3221 - 3229. 2016. 10.1021/acs.nanolett.6b00689. IF: 13.779


  • Capacitive DNA Detection Driven by Electronic Charge Fluctuations in a Graphene Nanopore

    Feliciano G.T., Sanz-Navarro C., Coutinho-Neto M.D., Ordejón P., Scheicher R.H., Rocha A.R. Physical Review Applied; 3 (3, 034003) 2015. 10.1103/PhysRevApplied.3.034003. IF: 0.000

  • Quasiparticle spectra of 2H-NbSe2: Two-band superconductivity and the role of tunneling selectivity

    Noat Y., Silva-Guillén J.A., Cren T., Cherkez V., Brun C., Pons S., Debontridder F., Roditchev D., Sacks W., Cario L., Ordejón P., García A., Canadell E. Physical Review B - Condensed Matter and Materials Physics; 92 (13, 134510) 2015. 10.1103/PhysRevB.92.134510. IF: 3.736

  • Tunneling and electronic structure of the two-gap superconductor MgB2

    Silva-Guillén J.A., Noat Y., Cren T., Sacks W., Canadell E., Ordejón P. Physical Review B - Condensed Matter and Materials Physics; 92 (6, 064514) 2015. 10.1103/PhysRevB.92.064514. IF: 3.736


  • Electronic properties of single-layer and multilayer transition metal dichalcogenides MX2 (M = Mo, W and X = S, Se)

    Roldán R., Silva-Guillén J.A., López-Sancho M.P., Guinea F., Cappelluti E., Ordejón P. Annalen der Physik; 526 (9-10): 347 - 357. 2014. 10.1002/andp.201400128.

  • Momentum dependence of spin-orbit interaction effects in single-layer and multi-layer transition metal dichalcogenides

    Roldán R., López-Sancho M.P., Guinea F., Cappelluti E., Silva-Guillén J.A., Ordejón P. 2D Materials; 1 (3, 034003) 2014. 10.1088/2053-1583/1/3/034003.


  • Manganese 3×3 and √3×√3-R30 â̂̃ structures and structural phase transition on w-GaN(0001̄) studied by scanning tunneling microscopy and first-principles theory

    Chinchore A.V., Wang K., Shi M., Mandru A., Liu Y., Haider M., Smith A.R., Ferrari V., Barral M.A., Ordejón P. Physical Review B - Condensed Matter and Materials Physics; 87 (16, 165426) 2013. 10.1103/PhysRevB.87.165426.

  • Tight-binding model and direct-gap/indirect-gap transition in single-layer and multilayer MoS2

    Cappelluti E., Roldán R., Silva-Guillén J.A., Ordejón P., Guinea F. Physical Review B - Condensed Matter and Materials Physics; 88 (7, 075409) 2013. 10.1103/PhysRevB.88.075409.


  • Calculation of core level shifts within DFT using pseudopotentials and localized basis sets

    García-Gil S., García A., Ordejón P. European Physical Journal B; 85 (7, 239) 2012. 10.1140/epjb/e2012-30334-5.

  • Carbon nanotubes as substrates for molecular spiropyran-based switches

    Malic, E.; Setaro, A.; Bluemmel, P.; Sanz-Navarro, C.F.; Ordejón, P.; Reich, S.; Knorr, A. Journal of Physics Condensed Matter; 24: 394006. 2012. .

  • Dielectric screening in extended systems using the self-consistent Sternheimer equation and localized basis sets

    Hübener H., Pérez-Osorio M.A., Ordejón P., Giustino F. Physical Review B - Condensed Matter and Materials Physics; 85 (24, 245125) 2012. 10.1103/PhysRevB.85.245125.

  • Electroresistance effect in ferroelectric tunnel junctions with symmetric electrodes

    Bilc D.I., Novaes F.D., Íñiguez J., Ordejón P., Ghosez P. ACS Nano; 6 (2): 1473 - 1478. 2012. 10.1021/nn2043324.

  • Insulating behavior of an amorphous graphene membrane

    Van Tuan D., Kumar A., Roche S., Ortmann F., Thorpe M.F., Ordejon P. Physical Review B - Condensed Matter and Materials Physics; 86 (12, 121408) 2012. 10.1103/PhysRevB.86.121408.

  • Performance of local orbital basis sets in the self-consistent Sternheimer method for dielectric matrices of extended systems

    Hubene, H.; Perez-Osorio, M.A.; Ordejon, P.; Giustino, F. European Physical Journal B; 85: 321. 2012. .

  • Y:BaZrO 3 perovskite compounds I: DFT study on the unprotonated and protonated local structures

    Cammarata A., Ordejón P., Emanuele A., Duca D. Chemistry - An Asian Journal; 7 (8): 1827 - 1837. 2012. 10.1002/asia.201100974.


  • An efficient implementation of a QM-MM method in SIESTA

    Sanz-Navarro C.F., Grima R., García A., Bea E.A., Soba A., Cela J.M., Ordejón P. Theoretical Chemistry Accounts; 128 (4): 825 - 833. 2011. 10.1007/s00214-010-0816-5.

  • Magnetism-dependent transport phenomena in hydrogenated graphene: From spin-splitting to localization effects

    Leconte N., Soriano D., Roche S., Ordejon P., Charlier J.-C., Palacios J.J. ACS Nano; 5 (5): 3987 - 3992. 2011. 10.1021/nn200558d.

  • Magnetoresistance and magnetic ordering fingerprints in hydrogenated graphene

    Soriano D., Leconte N., Ordejón P., Charlier J.-C., Palacios J.-J., Roche S. Physical Review Letters; 107 (1, 016602) 2011. 10.1103/PhysRevLett.107.016602.

  • Modulation of surface charge transfer through competing long-range repulsive versus short-range attractive interactions

    Fraxedas J., García-Gil S., Monturet S., Lorente N., Fernández-Torrente I., Franke K.J., Pascual J.I., Vollmer A., Blum R.-P., Koch N., Ordejón P. Journal of Physical Chemistry C; 115 (38): 18640 - 18648. 2011. 10.1021/jp2050838.

  • Oxygen surface functionalization of graphene nanoribbons for transport gap engineering

    Cresti A., Lopez-Bezanilla A., Ordejón P., Roche S. ACS Nano; 5 (11): 9271 - 9277. 2011. 10.1021/nn203573y.

  • Quantum transport in chemically modified two-dimensional graphene: From minimal conductivity to Anderson localization

    Leconte N., Lherbier A., Varchon F., Ordejon P., Roche S., Charlier J.-C. Physical Review B - Condensed Matter and Materials Physics; 84 (23, 235420) 2011. 10.1103/PhysRevB.84.235420.

  • Structural, dynamical, and electronic transport properties of modified DNA duplexes containing size-expanded nucleobases

    Blas J.R., Huertas O., Tabares C., Sumpter B.G., Fuentes-Cabrera M., Orozco M., Ordejón P., Luque F.J. Journal of Physical Chemistry A; 115 (41): 11344 - 11354. 2011. 10.1021/jp205122c.


  • Band selection and disentanglement using maximally localized Wannier functions: The cases of Co impurities in bulk copper and the Cu(111) surface

    Korytár R., Pruneda M., Junquera J., Ordejón P., Lorente N. Journal of Physics Condensed Matter; 22 (38, 385601) 2010. 10.1088/0953-8984/22/38/385601.

  • Damaging graphene with ozone treatment: A chemically tunable metal - Insulator transition

    Leconte N., Moser J., Ordejón P., Tao H., Lherbier A., Bachtold A., Alsina F., Sotomayor Torres C.M., Charlier J.-C., Roche S. ACS Nano; 4 (7): 4033 - 4038. 2010. 10.1021/nn100537z.

  • Density-wave instability in α- ( BEDT-TTF)2KHg(SCN) 4 studied by x-ray diffuse scattering and by first-principles calculations

    Foury-Leylekian P., Pouget J.-P., Lee Y.-J., Nieminen R.M., Ordejón P., Canadell E. Physical Review B - Condensed Matter and Materials Physics; 82 (13, 134116) 2010. 10.1103/PhysRevB.82.134116.

  • Electronic transport between graphene layers covalently connected by carbon nanotubes

    Novaes F.D., Rurali R., Ordejón P. ACS Nano; 4 (12): 7596 - 7602. 2010. 10.1021/nn102206n.

  • Orbital specific chirality and homochiral self-assembly of achiral molecules induced by charge transfer and spontaneous symmetry breaking

    Mugarza A., Lorente N., Ordejón P., Krull C., Stepanow S., Bocquet M.-L., Fraxedas J., Ceballos G., Gambardella P. Physical Review Letters; 105 (11, 115702) 2010. 10.1103/PhysRevLett.105.115702.

  • Preface: Phys. stat. sol. (c) 7/11-12

    Correia, A.; Sáenz, J.J.; Ordejon, P.; Roche, S. Physica Status Solidi (C) Current Topics in Solid State Physics; 7: 2593 - 2595. 2010. 10.1002/pssc.201060100.

  • Real-time TD-DFT simulations in dye sensitized solar cells: The electronic absorption spectrum of alizarin supported on TiO2 nanoclusters

    Sánchez-De-Armas R., Oviedo López J., San-Miguel M.A., Sanz J.F., Ordejón P., Pruneda M. Journal of Chemical Theory and Computation; 6 (9): 2856 - 2865. 2010. 10.1021/ct100289t.


  • Optimal strictly localized basis sets for noble metal surfaces

    García-Gil S., García A., Lorente N., Ordejón P. Physical Review B - Condensed Matter and Materials Physics; 79 (7, 075441) 2009. 10.1103/PhysRevB.79.075441.

  • Physica Status Solidi C: Preface

    Correia, A.; Sáenz, J.J.; Ordejón, P. Physica Status Solidi (C) Current Topics in Solid State Physics; 6: 2093 - 2095. 2009. 10.1002/pssc.200960073.

  • Tunneling spectroscopy in core/shell structured Fe/MgO nanospheres

    Martínez-Boubeta C., Balcells Li., Monty C., Ordejon P., Martínez B. Applied Physics Letters; 94 (6, 062507) 2009. 10.1063/1.3080657.


  • Band bending and quasi-2deg in the metallized β-SiC(001) surface

    Rurali R., Wachowicz E., Hyldgaard P., Ordejón P. Physica Status Solidi - Rapid Research Letters; 2 (5): 218 - 220. 2008. 10.1002/pssr.200802166.

  • The SIESTA method; Developments and applicability

    Artacho E., Anglada E., Diéguez O., Gale J.D., García A., Junquera J., Martin R.M., Ordejón P., Pruneda J.M., Sánchez-Portal D., Soler J.M. Journal of Physics Condensed Matter; 20 (6, 064208) 2008. 10.1088/0953-8984/20/6/064208.


  • GaS and InSe equations of state from single crystal diffraction

    J. Pellicer-Porres; E. Machado-Charry; A. Segura; S. Gilliland; E. Canadell; P. Ordejón; A. Polian; P. Munsch; A. Chevy y N. Guignot Physica Status Solidi (B): Basic Research; 2007. .

  • Interaction of copper organometallic precursors with barrier layers of Ti, Ta and W and their nitrides: a first-principles molecular dynamics study

    E. Machado; M. Kaczmarski; B. Braida; P. Ordejón; D. Garg; J. Norman; H. Cheng Journal of Molecular Modeling; 2007. .

  • Resistive and rectifying effects of pulling gold atoms at thiol-gold nanocontacts

    R. J. C. Batista; P. Ordejón; H. Chacham; E. Artacho Physical Review B; 2007. .

  • The Calculation of Free-Energiesin Semiconductors: Defects, Transitionsand Phase Diagrams

    E. R. Hernández; A. Antonelli; L. Colombo; P. Ordejón Topics in Applied Physics; 104: 115 - 140. 2007. .

  • Transport measurements under pressure in III¿IV layered semiconductors

    A. Segura; D. Errandonea; D. Martínez García; F. J. Manjón; A. Chevy; G. Tobías; P. Ordejón; E. Canadell Physica Status Solidi (B): Basic Research; 244: 162 - 168. 2007. .


  • Electron transport via local polarons at interface atoms

    Berthe, M.; Urbieta, A.; Perdigão, L.; Grandidier, B.; Deresmes, D.; Delerue, C.; Stiévenard, D.; Rurali, R.; Lorente, N.; Magaud, L.; Ordejón, P. Physical Review Letters; 97 2006. 10.1103/PhysRevLett.97.206801.


  • Self-doped titanium oxide thin films for efficient visible light photocatalysis: An example: Nonylphenol photodegradation

    Justicia, I.; Garcia, G.; Vázquez, L.; Santiso, J.; Ordejón, P.; Battiston, G.; Gerbasi, R.; Figueras, A. Sensors and Actuators, B: Chemical; 109: 52 - 56. 2005. 10.1016/j.snb.2005.03.021.