• RAPID COMMUNICATIONS
  • Electronic structure: wide-band, narrow-band, and strongly correlated systems
  • Semiconductors II: surfaces, interfaces, microstructures, and related topics
  • Surface physics, low-dimensional systems, and related topics
• ARTICLES
  • Electronic structure: wide-band, narrow-band, and strongly correlated systems
  • Semiconductors I: bulk
  • Semiconductors II: surfaces, interfaces, microstructures, and related topics
  • Surface physics, low-dimensional systems, and related topics

RAPID COMMUNICATIONS

Electronic structure: wide-band, narrow-band, and strongly correlated systems

Nonlocal dynamical correlations of strongly interacting electron systems M. H. Hettler, A. N. Tahvildar-Zadeh, M. Jarrell, T. Pruschke, and H. R. Krishnamurthy pp. R7475-R7479 [View PDF (111 kB) or Buy this Article (Use Article Pack) ]

Ab initio study of the dielectric properties of silicon and gallium arsenide using polarized Wannier functions Pablo Fernández, Andrea Dal Corso, and Alfonso Baldereschi pp. R7480-R7483 [View PDF (138 kB) or Buy this Article (Use Article Pack) ]

Coherent phonons from the CDW state in η-Mo4O11 Kisoda Kenji, Muneaki Hase, Hiroshi Harima, Shin-ichi Nakashima, Masahiko Tani, Kiyomi Sakai, Hiroshi Negishi, and Masasi Inoue pp. R7484-R7487 [View PDF (98 kB) or Buy this Article (Use Article Pack) ]

Development of bond-length alternation in very large carbon rings: LDA pseudopotential results Eric J. Bylaska, John H. Weare, and Ryoichi Kawai pp. R7488-R7491 [View PDF (92 kB) or Buy this Article (Use Article Pack) ]

Percolation-dominated conductivity in a conjugated-polymer-carbon-nanotube composite J. N. Coleman, S. Curran, A. B. Dalton, A. P. Davey, B. McCarthy, W. Blau, and R. C. Barklie pp. R7492-R7495 [View PDF (59 kB) or Buy this Article (Use Article Pack) ]

Optical conductivity of the Kondo insulator YbB12: Gap formation and low-energy excitations H. Okamura, S. Kimura, H. Shinozaki, T. Nanba, F. Iga, N. Shimizu, and T. Takabatake pp. R7496-R7499 [View PDF (92 kB) or Buy this Article (Use Article Pack) ]

Semiconductors II: surfaces, interfaces, microstructures, and related topics

Triangular-tiled arrangement of 7×7 and ‘1×1’ domains on Si(111) H. Hibino, Y. Homma, and T. Ogino pp. R7500-R7503 [View PDF (777 kB) or Buy this Article (Use Article Pack) ]

Stability of the c(4×8) structure in the adsorption of Pb in the (100) surface of elemental semiconductors Noboru Takeuchi pp. R7504-R7507 [View PDF (597 kB) or Buy this Article (Use Article Pack) ]

Zeeman splitting of excitons and biexcitons in single In0.60Ga0.40As/GaAs self-assembled quantum dots A. Kuther, M. Bayer, A. Forchel, A. Gorbunov, V. B. Timofeev, F. Schäfer, and J. P. Reithmaier pp. R7508-R7511 [View PDF (98 kB) or Buy this Article (Use Article Pack) ]

Frequency-dependent shot noise as a probe of electron-electron interaction in mesoscopic diffusive contacts K. E. Nagaev pp. R7512-R7515 [View PDF (103 kB) or Buy this Article (Use Article Pack) ]

Electron refraction in ballistic electron-emission microscopy studied by a superlattice energy filter J. Smoliner, R. Heer, C. Eder, and G. Strasser pp. R7516-R7519 [View PDF (86 kB) or Buy this Article (Use Article Pack) ]

Properties of the apparent metal-insulator transition in two-dimensional systems Y. Hanein, D. Shahar, J. Yoon, C. C. Li, D. C. Tsui, and Hadas Shtrikman pp. R7520-R7523 [View PDF (92 kB) or Buy this Article (Use Article Pack) ]

Conductance peak distributions in quantum dots at finite temperature: Signatures of the charging energy Y. Alhassid, M. Gökçedağ, and A. D. Stone pp. R7524-R7527 [View PDF (111 kB) or Buy this Article (Use Article Pack) ]

Transition between static and dynamic electric-field domain formation in weakly coupled GaAs/AlAs superlattices Naoki Ohtani, Norifumi Egami, Holger T. Grahn, Klaus H. Ploog, and Luis L. Bonilla pp. R7528-R7531 [View PDF (387 kB) or Buy this Article (Use Article Pack) ]

Absence of floating delocalized states in a two-dimensional hole gas S. C. Dultz, H. W. Jiang, and W. J. Schaff pp. R7532-R7535 [View PDF (319 kB) or Buy this Article (Use Article Pack) ]

Spatial evolution of hot-electron relaxation in quantum Hall conductors I. I. Kaya, G. Nachtwei, K. von Klitzing, and K. Eberl pp. R7536-R7539 [View PDF (306 kB) or Buy this Article (Use Article Pack) ]

Optical studies of ultrashort-period GaAs/AlAs superlattices grown on (In,Ga)As pseudosubstrate M. Rezki, A. M. Vasson, A. Vasson, P. Lefebvre, V. Calvo, R. Planel, and G. Patriarche pp. R7540-R7543 [View PDF (89 kB) or Buy this Article (Use Article Pack) ]

Surface physics, low-dimensional systems, and related topics

Anomaly in the anisotropy of the aluminum work function C. J. Fall, N. Binggeli, and A. Baldereschi pp. R7544-R7547 [View PDF (93 kB) or Buy this Article (Use Article Pack) ]

Superstructure formation and faceting in the Cu(210)-O system studied by scanning tunneling microscopy A. T. Wee, J. S. Foord, R. G. Egdell, and J. B. Pethica pp. R7548-R7551 [View PDF (707 kB) or Buy this Article (Use Article Pack) ]

Azimuthal dependence of classical over-barrier hopping diffusion of hydrogen on a vicinal Ni(111) surface E. Nabighian and X. D. Zhu pp. R7552-R7555 [View PDF (102 kB) or Buy this Article (Use Article Pack) ]

Activation energy for the decay of two-dimensional islands on Cu(100) Christian Klünker, James B. Hannon, Margret Giesen, Harald Ibach, Ghyslain Boisvert, and Laurent J. Lewis pp. R7556-R7559 [View PDF (160 kB) or Buy this Article (Use Article Pack) ]

ARTICLES

Electronic structure: wide-band, narrow-band, and strongly correlated systems

•	Magnetic breakdown in the organic conductor α-(BEDT-TTF)2KHg(SCN)4 in magnetic fields of up to 60 T M. M. Honold, N. Harrison, M.-S. Nam, J. Singleton, C. H. Mielke, M. Kurmoo, and P. Day pp. 7560-7564 [View PDF (121 kB) or Buy this Article (Use Article Pack) ]

•	Real-space multiple-scattering calculation and interpretation of x-ray-absorption near-edge structure A. L. Ankudinov, B. Ravel, J. J. Rehr, and S. D. Conradson pp. 7565-7576 [View PDF (225 kB) or Buy this Article (Use Article Pack) ]

•	Ab initio molecular-dynamics method based on the restricted path integral: Application to the electron plasma and liquid alkali metal Ki-dong Oh and P. A. Deymier pp. 7577-7584 [View PDF (156 kB) or Buy this Article (Use Article Pack) ]

•	Electronic structure and exchange interactions in the manganese-based pyrochlore oxides S. K. Mishra and S. Satpathy pp. 7585-7592 [View PDF (186 kB) or Buy this Article (Use Article Pack) ]

•	Experimental and theoretical study of electron momentum density of K6C60 and comparison to pristine C60 M. Marangolo, J. Moscovici, G. Loupias, S. Rabii, S. C. Erwin, C. Hérold, J. F. Marêché, and Ph. Lagrange pp. 7593-7598 [View PDF (134 kB) or Buy this Article (Use Article Pack) ]

•	Many-body band structure and Fermi surface of the Kondo lattice R. Eder, O. Rogojanu, and G.A. Sawatzky pp. 7599-7611 [View PDF (391 kB) or Buy this Article (Use Article Pack) ]

•	Charged and spin-excitation gaps in half-filled strongly correlated electron systems: A rigorous result Guang-Shan Tian pp. 7612-7618 [View PDF (175 kB) or Buy this Article (Use Article Pack) ]

•	Chiral liquids in one dimension: A non-Fermi-liquid class of fixed points Natan Andrei, Michael R. Douglas, and Andrés Jerez pp. 7619-7625 [View PDF (191 kB) or Buy this Article (Use Article Pack) ]

•	Electronic and phononic states of the Holstein-Hubbard dimer of variable length M. Acquarone, J. R. Iglesias, M. A. Gusmão, C. Noce, and A. Romano pp. 7626-7636 [View PDF (226 kB) or Buy this Article (Use Article Pack) ]

•	Model for aging in HCl-protonated polyaniline: Structure, conductivity, and composition studies A. Wolter, P. Rannou, J. P. Travers, B. Gilles, and D. Djurado pp. 7637-7647 [View PDF (183 kB) or Buy this Article (Use Article Pack) ]

•	Magneto-optical Kerr spectroscopy of palladium A. N. Yaresko, L. Uba, S. Uba, A. Ya. Perlov, R. Gontarz, and V. N. Antonov pp. 7648-7653 [View PDF (163 kB) or Buy this Article (Use Article Pack) ]

•	Biexcitons in π-conjugated oligomers: Intensity-dependent femtosecond transient-absorption study V. I. Klimov, D. W. McBranch, N. Barashkov, and J. Ferraris pp. 7654-7662 [View PDF (211 kB) or Buy this Article (Use Article Pack) ]

•	Application of relativistic scattering theory of x rays to diffraction anomalous fine structure in Cu E. Arola and P. Strange pp. 7663-7667 [View PDF (124 kB) or Buy this Article (Use Article Pack) ]

•	Polarized x-ray-absorption spectra of TiS2, TiSe2, and TiTe2 S. Bocharov, G. Dräger, D. Heumann, A. Šimůnek, and O. Šipr pp. 7668-7674 [View PDF (189 kB) or Buy this Article (Use Article Pack) ]

•	High-resolution angle-resolved photoemission study of LaSb H. Kumigashira, Hyeong-Do Kim, T. Ito, A. Ashihara, T. Takahashi, T. Suzuki, M. Nishimura, O. Sakai, Y. Kaneta, and H. Harima pp. 7675-7680 [View PDF (1780 kB) or Buy this Article (Use Article Pack) ]

•	Gauss, Wannier, and ultralocalized functions P. Zeiner, R. Dirl, and B. L. Davies pp. 7681-7688 [View PDF (229 kB) or Buy this Article (Use Article Pack) ]

•	Comprehensive analysis of intermolecular charge-transfer excited states in C60 and C70 films S. Kazaoui, N. Minami, Y. Tanabe, H. J. Byrne, A. Eilmes, and P. Petelenz pp. 7689-7700 [View PDF (189 kB) or Buy this Article (Use Article Pack) ]

Semiconductors I: bulk

•	Hybrid density-functional study of the vibrational frequency of a H2 molecule at the tetrahedral site of silicon Yasuharu Okamoto, Mineo Saito, and Atsushi Oshiyama pp. 7701-7706 [View PDF (117 kB) or Buy this Article (Use Article Pack) ]

•	Optically detected magnetic resonance study of an arsenic-antisite–arsenic-vacancy complex in GaAs F. K. Koschnick, K.-H. Wietzke, and J.-M. Spaeth pp. 7707-7716 [View PDF (430 kB) or Buy this Article (Use Article Pack) ]

•	Si-C atomic bond and electronic band structure of a cubic Si1-yCy alloy Y. Fu, M. Willander, P. Han, T. Matsuura, and J. Murota pp. 7717-7722 [View PDF (148 kB) or Buy this Article (Use Article Pack) ]

•	Neutral interstitial iron center in silicon studied by Zeeman spectroscopy AnnaLena Thilderkvist, Günter Grossmann, Mats Kleverman, and Hermann G. Grimmeiss pp. 7723-7733 [View PDF (280 kB) or Buy this Article (Use Article Pack) ]

•	Oxygen isoelectronic impurities in ZnTe: Photoluminescence and absorption spectroscopy M. J. Seong, I. Miotkowski, and A. K. Ramdas pp. 7734-7739 [View PDF (130 kB) or Buy this Article (Use Article Pack) ]

•	Ultrafast charge separation in β-substituted sexithiophene amorphous films G. Lanzani, G. Cerullo, S. Stagira, S. De Silvestri, and F. Garnier pp. 7740-7744 [View PDF (121 kB) or Buy this Article (Use Article Pack) ]

•	EPR and IR spectral properties of hydrogen-associated bulk and surface defects in SiO2: Ab initio calculations Gianfranco Pacchioni and Mirko Vitiello pp. 7745-7752 [View PDF (288 kB) or Buy this Article (Use Article Pack) ]

•	Carrier diffusion in Cd1-xMnxTe C. Moussu, I. Zaquine, A. Maruani, and R. Frey pp. 7753-7760 [View PDF (201 kB) or Buy this Article (Use Article Pack) ]

•	Comparison of calculated optical response in cubic and hexagonal II-VI semiconductors James L. Hughes and J. E. Sipe pp. 7761-7767 [View PDF (192 kB) or Buy this Article (Use Article Pack) ]

•	Time-dependent heat diffusion in semiconductors by electrons and phonons G. González de la Cruz and Yu. G. Gurevich pp. 7768-7773 [View PDF (134 kB) or Buy this Article (Use Article Pack) ]

•	Transport properties of polyaniline-cellulose-acetate blends Jérôme Planès, Andreas Wolter, Yasmina Cheguettine, Adam Proń, Françoise Genoud, and Maxime Nechtschein pp. 7774-7785 [View PDF (310 kB) or Buy this Article (Use Article Pack) ]

•	Thermopower investigation of n- and p-type GaN M. S. Brandt, P. Herbst, H. Angerer, O. Ambacher, and M. Stutzmann pp. 7786-7791 [View PDF (131 kB) or Buy this Article (Use Article Pack) ]

•	Coexistence of neutral and charged arenes in conducting diperylene hexafluorophosphate Gerda Fischer and Elmar Dormann pp. 7792-7794 [View PDF (82 kB) or Buy this Article (Use Article Pack) ]

Semiconductors II: surfaces, interfaces, microstructures, and related topics

•	Reflection anisotropy spectroscopy study of the near-surface electric fields in undoped, n- and p-doped low-temperature grown GaAs (001) Todd Holden, W. D. Sun, Fred H. Pollak, J. L. Freeouf, D. McInturff, and J. M. Woodall pp. 7795-7798 [View PDF (94 kB) or Buy this Article (Use Article Pack) ]

•	Comparison between ab initio theory and scanning tunneling microscopy for (110) surfaces of III-V semiconductors B. Engels, P. Richard, K. Schroeder, S. Blügel, Ph. Ebert, and K. Urban pp. 7799-7815 [View PDF (641 kB) or Buy this Article (Use Article Pack) ]

•	Gauge-invariant grid discretization of the Schrödinger equation Michele Governale and Carlo Ungarelli pp. 7816-7821 [View PDF (136 kB) or Buy this Article (Use Article Pack) ]

•	Interface effects on magnetopolarons in GaAs/AlxGa1-xAs quantum wells at high magnetic fields G. Q. Hai, F. M. Peeters, N. Studart, Y. J. Wang, and B. D. McCombe pp. 7822-7828 [View PDF (155 kB) or Buy this Article (Use Article Pack) ]

•	Binding energies of ground and excited donor states bound to X valleys in GaAs/AlAs type-II quantum wells Gleise N. Carneiro and Gerald Weber pp. 7829-7833 [View PDF (129 kB) or Buy this Article (Use Article Pack) ]

•	Localization at interfaces of imperfect AlSb/InAs heterostructures M. J. Shaw pp. 7834-7843 [View PDF (1738 kB) or Buy this Article (Use Article Pack) ]

•	Weak-localization magnetoresistance in quench-condensed lithium films Eric D. Black and John C. Price pp. 7844-7849 [View PDF (131 kB) or Buy this Article (Use Article Pack) ]

•	Properties of CdSe nanocrystal dispersions in the dilute regime: Structure and interparticle interactions Hedi Mattoussi, Andrew W. Cumming, Christopher B. Murray, Moungi G. Bawendi, and Raymond Ober pp. 7850-7863 [View PDF (292 kB) or Buy this Article (Use Article Pack) ]

•	Heterojunction band offsets and Schottky-barrier heights: Tersoff’s theory in the presence of strain C. Ohler, C. Daniels, A. Förster, and H. Lüth pp. 7864-7871 [View PDF (146 kB) or Buy this Article (Use Article Pack) ]

•	Quantum point contact on graphite surface Ç. Kılıç, H. Mehrez, and S. Ciraci pp. 7872-7881 [View PDF (328 kB) or Buy this Article (Use Article Pack) ]

•	Cotunneling and renormalization effects for the single-electron transistor Jürgen König, Herbert Schoeller, and Gerd Schön pp. 7882-7892 [View PDF (231 kB) or Buy this Article (Use Article Pack) ]

•	Dual response models for the fractional quantum Hall effect L. Cooper, I. I. Kogan, A. Lopez, and R. J. Szabo pp. 7893-7897 [View PDF (119 kB) or Buy this Article (Use Article Pack) ]

•	Fermi-hypernetted-chain study of unprojected wave functions to describe the half-filled state of the fractional quantum Hall effect O. Ciftja and S. Fantoni pp. 7898-7905 [View PDF (185 kB) or Buy this Article (Use Article Pack) ]

•	Influence of the exchange reaction on the electronic structure of GaN/Al junctions S. Picozzi, A. Continenza, S. Massidda, A. J. Freeman, and N. Newman pp. 7906-7912 [View PDF (283 kB) or Buy this Article (Use Article Pack) ]

•	Resonant Raman scattering and photoluminescence in SiOx/CdSe multiple quantum wells D. Nesheva, C. Raptis, and Z. Levi pp. 7913-7920 [View PDF (134 kB) or Buy this Article (Use Article Pack) ]

•	Size-dependent near-infrared photoluminescence from Ge nanocrystals embedded in SiO2 matrices Shinji Takeoka, Minoru Fujii, Shinji Hayashi, and Keiichi Yamamoto pp. 7921-7925 [View PDF (329 kB) or Buy this Article (Use Article Pack) ]

•	Role of the exchange of carriers in elastic exciton-exciton scattering in quantum wells C. Ciuti, V. Savona, C. Piermarocchi, A. Quattropani, and P. Schwendimann pp. 7926-7933 [View PDF (228 kB) or Buy this Article (Use Article Pack) ]

•

Coplanar and grazing incidence x-ray-diffraction investigation of self-organized SiGe quantum dot multilayers V. Holý, A. A. Darhuber, J. Stangl, S. Zerlauth, F. Schäffler, G. Bauer, N. Darowski, D. Lübbert, U. Pietsch, and I. Vávra pp. 7934-7943 [View PDF (1711 kB) or Buy this Article (Use Article Pack) ]

•	Dissociative adsorption of NH3 on Si(001)-(2×1) R. Miotto, G. P. Srivastava, and A. C. Ferraz pp. 7944-7949 [View PDF (674 kB) or Buy this Article (Use Article Pack) ]

•	Cl2 dissociation on Si(100)-(2×1): A statistical study by scanning tunneling microscopy I. Lyubinetsky, Z. Dohnálek, W. J. Choyke, and J. T. Yates pp. 7950-7957 [View PDF (7445 kB) or Buy this Article (Use Article Pack) ]

•	Surface acoustic waves in two-dimensional periodic elastic structures Yukihiro Tanaka and Shin-ichiro Tamura pp. 7958-7965 [View PDF (204 kB) or Buy this Article (Use Article Pack) ]

•	Hydrogen-boron interactions in p-type diamond J. Chevallier, B. Theys, A. Lusson, C. Grattepain, A. Deneuville, and E. Gheeraert pp. 7966-7969 [View PDF (72 kB) or Buy this Article (Use Article Pack) ]

•	Binding energy of bound excitons D0X in quantum wells J. L. Dunn, C. A. Bates, M. J. Pye, D. Boffety, A.-M. Vasson, A. Vasson, and J. Leymarie pp. 7970-7977 [View PDF (161 kB) or Buy this Article (Use Article Pack) ]

•

Degenerate four-wave mixing measurements on an exciton-photon coupled system in a semiconductor microcavity Masayuki Shirane, C. Ramkumar, Yu. P. Svirko, Hidekatsu Suzuura, Shin Inouye, Ryo Shimano, Takao Someya, Hiroyuki Sakaki, and Makoto Kuwata-Gonokami pp. 7978-7985 [View PDF (201 kB) or Buy this Article (Use Article Pack) ]

•	Polaron in a spherical quantum dot embedded in a nonpolar matrix Kazunori Oshiro, Koji Akai, and Mitsuru Matsuura pp. 7986-7993 [View PDF (178 kB) or Buy this Article (Use Article Pack) ]

•	Mesoscopic pointlike defects in semiconductors: Deep-level energies D. D. Nolte pp. 7994-8001 [View PDF (157 kB) or Buy this Article (Use Article Pack) ]

•	Edge and bulk electron states in a quasi-one-dimensional metal in a magnetic field: The semi-infinite Wannier-Stark ladder Victor M. Yakovenko and Hsi-Sheng Goan pp. 8002-8008 [View PDF (168 kB) or Buy this Article (Use Article Pack) ]

•	Strong localization of electrons in quasi-one-dimensional conductors Yu. B. Khavin, M. E. Gershenson, and A. L. Bogdanov pp. 8009-8019 [View PDF (225 kB) or Buy this Article (Use Article Pack) ]

•	Electrical band-gap energy of porous silicon and the band offsets at the porous-silicon/crystalline-silicon heterojunction measured versus sample temperature J. T. Frederiksen, P. G. Melcher, and E. Veje pp. 8020-8024 [View PDF (80 kB) or Buy this Article (Use Article Pack) ]

Surface physics, low-dimensional systems, and related topics

•	X-ray speckles from an optical grating Binhua Lin, Mark L. Schlossman, Mati Meron, Scott M. Williams, Zhengqing Huang, and P. James Viccaro pp. 8025-8037 [View PDF (300 kB) or Buy this Article (Use Article Pack) ]

•	First-principles theory of inelastic currents in a scanning tunneling microscope K. Stokbro, Ben Yu-Kuang Hu, C. Thirstrup, and X. C. Xie pp. 8038-8041 [View PDF (145 kB) or Buy this Article (Use Article Pack) ]

•	Scanning tunneling microscopy of the misfit-layer compound (SmS)1.19NbS2 Youichi Ohno pp. 8042-8049 [View PDF (1119 kB) or Buy this Article (Use Article Pack) ]

•	First-principles study of the surfaces of zirconia A. Christensen and Emily A. Carter pp. 8050-8064 [View PDF (2278 kB) or Buy this Article (Use Article Pack) ]

•	Structure and microstructure of La1-xCaxMnO3-δ thin films prepared by pulsed laser deposition O. I. Lebedev, G. Van Tendeloo, S. Amelinckx, B. Leibold, and H.-U. Habermeier pp. 8065-8074 [View PDF (3603 kB) or Buy this Article (Use Article Pack) ]

•	Relaxations of TiO2- and SrO-terminated SrTiO3 (001) surfaces Zhi-Qiang Li, Jia-Lin Zhu, C. Q. Wu, Z. Tang, and Yoshiyuki Kawazoe pp. 8075-8078 [View PDF (89 kB) or Buy this Article (Use Article Pack) ]

•	Electron relaxation in disordered gold films B. I. Belevtsev, Yu. F. Komnik, and E. Yu. Beliayev pp. 8079-8086 [View PDF (174 kB) or Buy this Article (Use Article Pack) ]

•	Derivation of inelastic-electron-scattering cross sections from quantitative analysis of reflection-electron-energy-loss spectra Y. F. Chen pp. 8087-8096 [View PDF (223 kB) or Buy this Article (Use Article Pack) ]

•	Calculations of near-edge x-ray-absorption spectra of gas-phase and chemisorbed molecules by means of density-functional and transition-potential theory L. Triguero, L. G. Pettersson, and H. Ågren pp. 8097-8110 [View PDF (269 kB) or Buy this Article (Use Article Pack) ]

•	Deformations of quasi-two-dimensional electron gas clusters S. M. Reimann, M. Koskinen, J. Helgesson, P. E. Lindelof, and M. Manninen pp. 8111-8119 [View PDF (285 kB) or Buy this Article (Use Article Pack) ]

•	Analysis of quantum conductance of carbon nanotube junctions by the effective-mass approximation Ryo Tamura and Masaru Tsukada pp. 8120-8124 [View PDF (138 kB) or Buy this Article (Use Article Pack) ]