General data

Keyword: ITERAT_EPS
0.0 = EPSITE

Keyword: MAXANTIOSC
1 = NULAST

These two parameters govern the termination of the HF iterations according to the achieved stability of solutions. The stability of the HF energy has been defined in (I-37) as the difference between the total energies calculated from the single-particle energies and from the Skyrme functional. The HF iterations continue until the absolute value of the stability is smaller than EPSITE (in MeV) over NULAST consecutive iterations. When this condition is fulfilled, iteration procedure terminates and the final results are printed. This allows for an automated adjustment of the number of iterations which are required to achieve a given level of convergence. The number of iterations NOITER, Section 3.1 of II, can now be set to a large value at which the iterations terminate if a stable solution is not found.

The default value of EPSITE=0.0 ensures that whenever this new option is not used, the code HFODD (v1.75r) behaves as that in version (v1.60r). If a non-zero value of EPSITE is used, a non-zero value of NULAST has to be used too. In practice, a value of NULAST=5 prevents an accidental termination of iterations in all cases when the stability energy changes the sign, but the solution is not yet self-consistent.

Keyword: PING-PONG
0.0, 3 = EPSPNG, NUPING

The code is able to detect the ``ping-pong'' divergence described in Section 2.6, i.e., the situation when the HF iteration procedure gives alternating results in every second iteration. Upon continuing the iteration, both sequences of results, i.e., those which correspond to the iteration numbers being even and odd, stay different but perfectly stable, and hence the correct self-consistent solution is never attained.

The code recognizes such a situation by calculating the averages and variances of the stability energy (I-37), separately in the even and in the odd sequences of results, over the last NUPING pairs of iterations. The ``ping-pong'' divergence condition occurs when both variances become a factor EPSPNG smaller than the absolute value of the difference of the corresponding averages, i.e., when

   where    and    Here, n denotes the number of the last accomplished HF iteration, and $\delta{\cal E}_{n'}$ denotes the stability energy (I-37) obtained in the n'-th iteration.

The default value of EPSPNG=0.0 ensures that whenever this new option is not used, the code HFODD (v1.75r) behaves as that in version (v1.60r). If a non-zero value of EPSPNG is used, a value of NUPING>1 has to be used too. In practice, values of EPSPNG=0.01 and NUPING=3 allow for an efficient detection of the ``ping-pong'' divergence condition.

Upon discovering the ``ping-pong'' divergence, the HF iterations are terminated and a table of absolute values of maximum differences of single-particle observables between the two sequences of iterations is printed, see Sec. 2.6 and Table 1. These maximum differences are determined for states in each of the charge-parity-signature (or charge-simplex) blocks, and separately for particle and hole states. Whenever such a maximum difference is found for a particle state and for a hole state with adjacent indices, such a pair is proposed as a candidate for the diabatic blocking calculation, see Secs. 2.6 and 3.2.

Keyword: CHAOTIC
0 = NUCHAO

The code is able to detect the ``chaotic'' divergence which occurs when the HF iterations give results which chaotically vary from one iteration to another one. The code recognizes such a divergence by finding the local maxima M<sub>k</sub>, k=1,2,..., in the sequence of absolute values of the stability energies (I-37), obtained in the entire series of the HF iterations performed. The ``chaotic'' divergence condition occurs when the code finds NUCHAO positive differences M_k-M_k-1. When this condition occurs, iteration procedure terminates and the final results are printed.

For NUCHAO=0 (the default value) the code does not check whether the ``chaotic'' divergence occurs or not. In practice, a value of NUCHAO=5 allows for an efficient detection of the ``chaotic'' divergence condition. However, for a small value of NUCHAO and a small value of EPSPNG, the ``ping-pong'' divergence can sometimes be mistaken for the ``chaotic'' divergence. If one is interested in the diabatic-blocking data, printed after the ``ping-pong'' divergence, the recommended value of NUCHAO=5 should be increased to 10 or more.

Keyword: PHASESPACE
	0, 0, 0, 0 =	NUMBSP(0,0), NUMBSP(1,0),
		NUMBSP(0,1), NUMBSP(1,1)

Numbers of the lowest mean-field eigenstates which are kept after the diagonalization of the mean-field Hamiltonians in the four simplex-charge blocks: (s,q)=(+i,n), (-i,n), (+i,p), (-i,p). All other eigenstates are discarded. If any of these numbers is equal to zero (the default value), the code sets it equal to the number of neutrons IN_FIX (for q=n) or protons IZ_FIX (for q=p), see Section 3.1 of II.

For calculations without pairing, the user is responsible for using values of NUMBSP large enough to accommodate all wave functions which might be useful for the required vacuum and particle-hole configurations, see Section 3.4 of II. In practice, the use of the default values described above is recommended as a safe option. The execution time is almost independent of NUMBSP. The size of the matrices defined by the NDSTAT parameter can be reduced by the user for smaller values of NUMBSP.