The electron-phonon interaction contribution to the electronic energies is included in density functional total energy calculations with ab initio pseudopotentials via the formalism of Allen [Phys. Rev. B, 18 5217 (1978)] to obtain the temperature dependent electronic structure of diamond and silicon. This method allows us to obtain the thermally-averaged ab initio electronic structure in a straightforward and computationally inexpensive way. Our investigations on the finite temperature electronic structure of diamond and silicon bring out that a new criterion, that of temperature transferability, is required in the input ab initio pseudopotentials for temperature dependent studies. The temperature transferability of the Troullier-Martins pseudopotentials used in this work is strongly dependent on the cut-off radius and the inclusion of the unbound 3d 0 state. The finite temperature indirect band gaps are highly sensitive to the choice of cut-off radius used in the pseudopotentials. The finite temperature band structures and density of states show that thermal vibrations affect the electron energies throughout the valence and conduction band. We compare our results on the band gap shifts with that due to the Debye-Waller term in the Allen-Heine theory and discuss the observed differences in the zero point and high temperature band gap shifts. Although, the electron energy shifts in the highest occupied valence band and lowest unoccupied conduction band enable to obtain the changes in the indirect and direct band gaps at finite temperatures, the shifts in other electronic levels with temperature enable investigations into the finite temperature valence charge distribution in the bonding region. Thus, we demonstrate that the Allen theory provides a simple and theoretically justified formalism to obtain finite temperature valence electron charge densities that go beyond the rigid pseudo-atom approximation.

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Background: Inguinal hernia repair is a common surgical procedure. Chronic pain occurs in 5-10% after the inguinal hernia repair. This study is aimed to evaluate post-operative analgesia efficacy of ultrasound guided transverse abdominal plane (TAP) block in unilateral hernia surgery. Aims and Objective: The present study aimed to evaluate the post-operative pain scoring at ½, 2,4,6,12,18 and 24 hours duration on basis of pain intensity using Visual Analogue Scale (VAS). Total requirement of analgesic drug in first 24 hours. To compare time for first rescue analgesia. Material and Method: A total of 80(n=80) patients of ASA I and II grade in the age group of 20 to 65 years undergoing unilateral hernia surgery. They were randomized into two groups. Lumbar puncture was done at L3-L4 space through a standard 25 G quincke spinal needle in sitting position of patient. Drug 0.5% hyperbaric bupivacaine 3.5 ml was administered intrathecally as a single dose in all patient. Study group: Patients received TAP block with Ropivacaine (0.5%) 20 ml after completion of surgery. Control group: Patients not received TAP block and was given injection diclofenac on demand for postoperative analgesia. The primary outcome was measured as patient-reported pain intensity using VAS. Results: VAS score was significantly lower in study group post-operatively at all time intervals(P<0.0001). The 24-h diclofenac consumption was significantly less in study group compared to control group (93.7±32.88mg vs. 204.3±44.89 mg, P< 0.0001). Time for first rescue analgesia was significantly more in study group as compared to control group (635.66±312.2 minutes vs. 210±140.7 minutes, p<0.0001) Conclusion: TAP block provided excellent post-operative analgesia in the first 24 h.