Ejemplo n.º 1
0
        private int GetGreenIndex(RpaParams[] plist)
        {
            if (plist.Length == 1)
                return 0;

            Console.WriteLine();
            Console.WriteLine("Found {0} Green's functions.", plist.Length);

            for(;;)
            {
                Console.Write("Enter index to use (1-{0}): ", plist.Length);
                int index;

                if (int.TryParse(Console.ReadLine(), out index) == false)
                    continue;

                Console.WriteLine();
                Console.WriteLine("Chose Green's function index {0}.", index);
                Console.WriteLine("   Temperature: {0}", plist[index].Temperature);
                Console.WriteLine("   Frequency: {0}", plist[index].Frequency);
                Console.WriteLine("   Mu: {0}", plist[index].ChemicalPotential);
                Console.WriteLine();
                Console.Write("Is this ok (y/n)? ");

                var key = Console.ReadKey();

                if (key.Key == ConsoleKey.Y)
                {
                    return index;
                }
            }
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Sorts by temperature, chemical potential, frequency, qindex.
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        public static int QIndexComparison(RpaParams x, RpaParams y)
        {
            if (x.Temperature != y.Temperature)
                return x.Temperature.CompareTo(y.Temperature);

            if (x.ChemicalPotential != y.ChemicalPotential)
                return x.ChemicalPotential.CompareTo(y.ChemicalPotential);

            if (x.Frequency != y.Frequency)
                return x.Frequency.CompareTo(y.Frequency);

            return x.Qindex.CompareTo(y.Qindex);
        }
Ejemplo n.º 3
0
        double InteractionAdjustment(List <RpaParams> rpa, Matrix[] S, Matrix[] C, TightBinding tb)
        {
            double    largest       = double.MinValue;
            RpaParams largestParams = null;
            bool      Cdiv          = false;

            for (int i = 0; i < rpa.Count; i++)
            {
                RpaParams p  = rpa[i];
                Matrix    x0 = p.X0;

                double lv = LargestPositiveEigenvalue(x0 * S[i]);

                if (lv > largest)
                {
                    largest       = lv;
                    largestParams = p;
                    Cdiv          = false;
                }

                lv = LargestPositiveEigenvalue(-x0 * C[i]);

                if (lv > largest)
                {
                    largest       = lv;
                    largestParams = p;
                    Cdiv          = true;
                }
            }

            if (largest >= 1)
            {
                Output.WriteLine("Interaction should be reduced to avoid divergence.", largest);
            }

            Output.WriteLine("Largest eigenvalue of denominator found at:");
            Output.WriteLine("    Eigenvalue: {0}", largest);
            Output.WriteLine("    {0} susceptibility", Cdiv ? "Charge" : "Spin");
            Output.WriteLine("    q = {0}", largestParams.QptValue);
            Output.WriteLine("    Temperature = {0}", largestParams.Temperature);
            Output.WriteLine("    Chemical Potential = {0}", largestParams.ChemicalPotential);
            Output.WriteLine("    Frequency = {0}", largestParams.Frequency);

            largest /= tb.Interactions.MaxEigenvalue;

            Output.WriteLine();
            return(1 / largest);
        }
Ejemplo n.º 4
0
        private Matrix[] CalcGreenFunction(TightBindingSuite.TightBinding tb, RpaParams p, KptList kmesh)
        {
            int orbitalCount = tb.Orbitals.Count;
            Matrix[] retval = new Matrix[kmesh.Kpts.Count];

            Complex denomFactor = new Complex(0, p.Temperature);

            for (int k = 0; k < kmesh.Kpts.Count; k++)
            {
                retval[k] = new Matrix(orbitalCount, orbitalCount);

                Matrix hamilt = tb.CalcHamiltonian(kmesh.Kpts[k].Value);
                Matrix vals, vecs;
                hamilt.EigenValsVecs(out vals, out vecs);

                for (int i = 0; i < orbitalCount; i++)
                {
                    for (int j = 0; j < orbitalCount; j++)
                    {
                        for (int n = 0; n < orbitalCount; n++)
                        {
                            var wfk = new Wavefunction(orbitalCount);

                            wfk.Energy = vals[n, 0].RealPart;

                            for (int c = 0; c < vecs.Rows; c++)
                            {
                                wfk.Coeffs[c] = vecs[c, n];
                            }

                            Complex coeff =
                                wfk.Coeffs[i].Conjugate() *
                                wfk.Coeffs[j];

                            Complex g = 1.0 / (p.Frequency + p.ChemicalPotential - wfk.Energy + denomFactor);

                            retval[k][i, j] += g * coeff;
                        }
                    }
                }

            }

            return retval;
        }
Ejemplo n.º 5
0
        private Matrix[] CalcGreenFunction(TightBindingSuite.TightBinding tb, RpaParams p, KptList kmesh)
        {
            int orbitalCount = tb.Orbitals.Count;
            Matrix[] retval = new Matrix[kmesh.Kpts.Count];

            Complex denomFactor = new Complex(0, p.Temperature);

            for (int k = 0; k < kmesh.Kpts.Count; k++)
            {
                retval[k] = new Matrix(orbitalCount, orbitalCount);

                Matrix hamilt = tb.CalcHamiltonian(kmesh.Kpts[k].Value);
                Matrix vals, vecs;
                hamilt.EigenValsVecs(out vals, out vecs);

                for (int i = 0; i < orbitalCount; i++)
                {
                    for (int j = 0; j < orbitalCount; j++)
                    {
                        for (int n = 0; n < orbitalCount; n++)
                        {
                            var wfk = new Wavefunction(orbitalCount);

                            wfk.Energy = vals[n, 0].RealPart;

                            for (int c = 0; c < vecs.Rows; c++)
                            {
                                wfk.Coeffs[c] = vecs[c, n];
                            }

                            Complex coeff =
                                wfk.Coeffs[i].Conjugate() *
                                wfk.Coeffs[j];

                            Complex g = 1.0 / (p.Frequency + p.ChemicalPotential - wfk.Energy + denomFactor);

                            retval[k][i, j] += g * coeff;
                        }
                    }
                }

            }

            return retval;
        }
Ejemplo n.º 6
0
        /// <summary>
        /// Sorts by temperature, chemical potential, frequency, qindex.
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        public static int QIndexComparison(RpaParams x, RpaParams y)
        {
            if (x.Temperature != y.Temperature)
            {
                return(x.Temperature.CompareTo(y.Temperature));
            }

            if (x.ChemicalPotential != y.ChemicalPotential)
            {
                return(x.ChemicalPotential.CompareTo(y.ChemicalPotential));
            }

            if (x.Frequency != y.Frequency)
            {
                return(x.Frequency.CompareTo(y.Frequency));
            }

            return(x.Qindex.CompareTo(y.Qindex));
        }
Ejemplo n.º 7
0
        void Run(string inputfile)
        {
            using (StreamWriter w = new StreamWriter("gplot.out"))
            {
                Output.SetFile(w);

                TightBindingSuite.TightBinding tb = new TightBindingSuite.TightBinding();
                tb.LoadTB(inputfile);

                RpaParams p = new RpaParams(0, Vector3.Zero, tb.TemperatureMesh[0], tb.FrequencyMesh[0], tb.MuMesh[0]);
                KptList kmesh = KptList.GenerateMesh(
                    tb.Lattice, tb.KMesh.Mesh, null, tb.Symmetries, true);

                Matrix[] green = CalcGreenFunction(tb, p, kmesh);

                while (true)
                {
                    WriteGreenFunction(tb, green, kmesh);
                };
            }
        }
Ejemplo n.º 8
0
        private void CalcSusceptibility(TightBinding tb, KptList qpts, List <RpaParams> rpa)
        {
            Matrix ident = Matrix.Identity(tb.Orbitals.Count * tb.Orbitals.Count);

            Matrix[] S, C;
            CalcSpinChargeMatrices(tb, rpa, out S, out C);

            Output.WriteLine("Calculating X0...");


            RpaThreadInfo[] threadInfos = CreateThreadInfos(tb, rpa, qpts);

            Output.WriteLine("Using {0} threads.", threads);

            for (int i = 0; i < threadInfos.Length; i++)
            {
                RunRpaThread(threadInfos[i]);

                if (i == 0)
                {
                    Thread.Sleep(20);
                }
            }

            bool threadsRunning;

            do
            {
                threadsRunning = false;

                for (int i = 0; i < threadInfos.Length; i++)
                {
                    if (threadInfos[i].Thread.ThreadState == ThreadState.Running)
                    {
                        threadsRunning = true;
                    }
                }

                Thread.Sleep(10);
            } while (threadsRunning);

            Output.WriteLine();
            Output.WriteLine("Bare susceptibility calculation completed.");
            Output.WriteLine();

            double factor = InteractionAdjustment(rpa, S, C, tb);

            if (tb.Interactions.AdjustInteractions)
            {
                Output.WriteLine("Multiplying interactions by {0}.", factor);

                for (int i = 0; i < rpa.Count; i++)
                {
                    S[i] *= factor;
                    C[i] *= factor;
                }
            }
            else if (factor < 1)
            {
                Output.WriteLine("WARNING:  There will be divergent geometric series.");
                Output.WriteLine("          Interpret results with care!");
            }

            Output.WriteLine();
            Output.WriteLine("Calculating dressed susceptibilities.");
            Output.WriteLine();

            RpaParams largestParams = null;
            double    largest       = 0;
            string    indices       = "";
            bool      charge        = false;

            for (int i = 0; i < rpa.Count; i++)
            {
                Matrix s_denom = (ident - S[i] * rpa[i].X0);
                Matrix c_denom = (ident + C[i] * rpa[i].X0);

                Matrix s_inv = s_denom.Invert();
                Matrix c_inv = c_denom.Invert();

                System.Diagnostics.Debug.Assert((s_denom * s_inv).IsIdentity);

                rpa[i].Xs = rpa[i].X0 * s_inv;
                rpa[i].Xc = rpa[i].X0 * c_inv;

                for (int l1 = 0; l1 < tb.Orbitals.Count; l1++)
                {
                    for (int l2 = 0; l2 < tb.Orbitals.Count; l2++)
                    {
                        for (int l3 = 0; l3 < tb.Orbitals.Count; l3++)
                        {
                            for (int l4 = 0; l4 < tb.Orbitals.Count; l4++)
                            {
                                int a = GetIndex(tb, l1, l2);
                                int b = GetIndex(tb, l3, l4);

                                bool found = false;

                                if (rpa[i].Xs[a, b].MagnitudeSquared > largest)
                                {
                                    largest = rpa[i].Xs[a, b].MagnitudeSquared;
                                    charge  = false;
                                    found   = true;
                                }
                                if (rpa[i].Xc[a, b].MagnitudeSquared > largest)
                                {
                                    largest = rpa[i].Xc[a, b].MagnitudeSquared;
                                    charge  = true;
                                    found   = true;
                                }
                                if (found == false)
                                {
                                    continue;
                                }

                                indices       = string.Format("{0}{1}{2}{3}", l1, l2, l3, l4);
                                largestParams = rpa[i];
                            }
                        }
                    }
                }
            }

            Output.WriteLine("Largest susceptibility found at:");
            Output.WriteLine("    {0} susceptibility: {1}", charge ? "Charge" : "Spin", Math.Sqrt(largest));
            Output.WriteLine("    Indices: {0}", indices);
            Output.WriteLine("    Temperature: {0}", largestParams.Temperature);
            Output.WriteLine("    Frequency: {0}", largestParams.Frequency);
            Output.WriteLine("    Chemical Potential: {0}", largestParams.ChemicalPotential);
            Output.WriteLine("    Q: {0}", largestParams.QptValue);
        }
Ejemplo n.º 9
0
        void Run(string inputfile)
        {
            using (StreamWriter w = new StreamWriter("gplot.out"))
            {
                Output.SetFile(w);

                TightBindingSuite.TightBinding tb = new TightBindingSuite.TightBinding();
                tb.LoadTB(inputfile);

                RpaParams p = new RpaParams(0, Vector3.Zero, tb.TemperatureMesh[0], tb.FrequencyMesh[0], tb.MuMesh[0]);
                KptList kmesh = KptList.GenerateMesh(
                    tb.Lattice, tb.KMesh.Mesh, null, tb.Symmetries, true);

                Matrix[] green = CalcGreenFunction(tb, p, kmesh);

                while (true)
                {
                    WriteGreenFunction(tb, green, kmesh);
                };
            }
        }